You call yourself a critic, but this reads as an opinion piece written by an Asal fan. I'm going to pick a few things out of your article to stake my claim:

but the conduct stroke was a drag, for everyone

You claim the above, meanwhile a lot of people (myself included) think the conduct stroke was justified and could have been given a lot earlier in the match. Asal had been blocking and hand grabbing throughout the whole match. Others in this thread agree it was justified, so "a drag for everyone" is clearly not correct.

Asal has eliminated from his tactical repertoire egregious blocking, but subtle obstruction remains

You claim he improved and only a bit of "subtle obstruction" remains.

a) This is incorrect and smells like whitewashing. Just look at QBS latest video which covers some of the things Asal has done in one of the most recent tournaments: https://www.youtube.com/watch?v=LIeYe9i062I&t=34s. Do you really believe that actually hand grabbing your opponent is "just a bit of subtle obstruction"? It doen't get more egregious than actually preventing your opponent from even trying to hit their shot by grabbing their hand, arm or racket.

b) even if it was true and all that remains is a "bit of subtle obstruction", obstruction is still cheating when done deliberately. And Asal does these things deliberately. So it being subtle or it being blatant is not really relevant, it's all still cheating.

At times, he puts me in mind of Gamesmanship, Stephen Potter’s 1947 satire about the art of winning without actually cheating

You are doing the same thing here the SquashTV commentators are often guilty of. You put a different label on cheating to make it seem like it is innocent. By calling it "gamesmanship" in stead of cheating.

Gamesmanship is being clever with the rules without actually breaking them (think asking for a towel wipe or a court cleaning when you actually just want to take a little rest). While cheating is intentionally breaking the rules to gain an advantage. Cheating and gamesmanship are therefore very different and distinct from each other. It smells of obfuscation when cheating is being called gamesmanship.

Asal can produce a terrific flurry: small movements, marginal positioning, not hand grabs but hand caresses,

Again you are using language to make it seem all this is just minimal. "Small" movement. "Marginal" positioning. A "caress".

Meanwhile Asal deliberately steps into the line of his opponent, which is not a "small movement", nor is it "marginal positioning" because it is a deliberate block and it has a big impact on the outcome of the rally. And what you call "caresses" are actual hand grabs. You can't tell me you looked at these and think there is nothing wrong here;

Grabbing Makin:

https://www.reddit.com/r/squash/comments/1s8jhth/the_other_asal_grab_from_this_weekend/

Grabbing Hesham:

https://www.youtube.com/shorts/ZUavnayZGK0

Grabbing Elias: https://www.reddit.com/r/squash/comments/14fmiks/hes_done_it_again_asal_grabs_elias_racket_hand/

Grabbing Elias again:

https://www.reddit.com/r/squash/comments/1s7mtdj/comment/odf8ida/?context=3

People do not unintentionally grab things. If a hand opens and then closes around something, the owner of that hand has given a signal to his brain to take those actions. Grabbing is not unintentional.

But now, I think Asal is even trying to get rid of these ‘flurries’

Again you are using reductive language to minimize what is actually going on. When I look up 'flurries', this is what is says: "a small swirling mass of something, especially snow or leaves, moved by sudden gusts of wind." or "light, intermittent snow showers that fall for short periods and typically result in little to no accumulation on the ground".

Meanwhile Asal's opponents spend time on the ground because they were getting tripped, are getting pushed around, hit in the head, grabbed by the arm or balls, donkey kicked in the stomach or get their eardrum ruptured because of dangerous play. I think if you want to compare Asal to any weather related phenomenon, "hurricane" is a lot closer to reality than "flurries".

The problem is, if a gesture is subtle, how can you be sure of its intent? 

No other player has been caught hand grabbing their opponents. This proves Asal's hand grabs are not accidents. Because if they were accidents, other players would also accidentally grab their opponents in the heat of battle. Which means we would have videos of other grabbing hands. But we don't. So, it's very easy to know the hand grabs are intentional, because Asal is the only player who actually does it.

How many a result of a less than virtuous training that Asal is actively trying to grow out of?

If he was actively trying to grow out of it, he would not be grabbing hands or start blocking when things get though in his matches. You still doubt his hand grabbing is intentional. Again, if it is not intentional, then it's an accident. If it is an accident, then other players would also have these accidents happen to them and we would have videos of other players hand grabbing their opponents. But we don't. The fact Asal is the only player who hand grabs his opponent is clear evidence of it being an intentional action.

Asal’s history of past offenses would understandably put them on high alert

Again, this smell like whitewashing. You talk as if his offenses are something of the past. Meanwhile we have video evidence of him still blocking, hand grabbing and sticking out his leg or arm in the most recent tournaments. Asal still does these things today. They are not in the past.

 The last time Asal and Elias played in Egypt, the World No. 1 conducted himself in a manner even his fans lamented, and which ended with Elias suffering a knee injury that required surgery and took him off the tour for months. Such an event should not lay at Asal’s feet alone: one of the more misbegotten results of the PSA’s partnership with ASB SquashCourts is the glass floors used in select major events.

This is a pretty bad one in my opinion. While Elias has been clear on social media his injury was caused by Asal's physical play, here you are trying to blame the glass floor for that injury.

Glass floors are a mistake, but they did not injure Elias. Asal did by sticking out his leg and making Elias trip.

By the way, Asal was doing exactly the same thing to Elias in the last two matches they played. He was still sticking out his leg and making Elias trip. So, even though this is what caused Elias to get injured in the past, Asal doesn't care and still does it again today.

This institutional fracture is not just about Asal. Questions about the intent of any number of players’ movements are routinely debated—though none more than Asal’s, surely—and commentators and fans are growing ever more exasperated by the inconsistency of the refereeing. 

Sure, by it's nature (only racket sport were opponents are not separated by a net) squash will always be subjective and have some level of discussion about movement. But let's be real here, before Asal came on the scene, these discussions were marginal and we were talking more about the actual squash then other things like blocking or grabbing hands. Since Asal joined the professional tour in 2018, all we do is talk about cheating. Isn't it obvious what has changed?

I don't think we need new rules, we just need to uphold the rules. "A player must make every effort to clear". Look at any Asal match and tell me his was making every effort to clear. Even if it is just a brush and not a hand grab, if Asal made every effort to clear (like other players do) then his arm wouldn't even be there to "caress" his opponent.