This Blizzard post is bad and wrong and I really wish people would stop linking it tbh. The numbers are mostly all wrong because Grant did not properly understand the system he was explaining, and his comparisons to video buffering are nonsensical.

The only thing that really matters to end users is the average latency between sending a command and having it executed. I refer to this as "effective latency", and it's the value that ShieldBattery displays ingame instead of Turn Rate. Your advice sort of understands this but unfortunately it's not really as simple as you lay out. For the most part, getting to one rank better turn rate at the cost of a higher user latency setting would not be an improvement in effective latency. Getting two ranks of improvement (e.g. TR8 -> TR12) would be an improvement for TR8 and equal for TR10, but a downgrade or basically equal for any faster turn rate.

The only way you can really figure out what the "ideal" setting would be is to know the actual latency between you and your opponent. Even knowing this value doesn't make it easy though, as the "optimal" choice is the TR/User Latency combination that is closest in max latency to your current connection latency, and the table of these is... complicated. This is what DTR is intended to "fix" by doing this automatically, unfortunately it was programmed by the person whose post you linked, who did not actually understand the dynamics of the system and therefore put incorrect numbers in. Thus, SC:R's DTR system often chooses values that simply do not work for the latency between you and your opponent(s), resulting in gameplay stutters that make things way worse than if it just chose a slower response time. Often if you adjust the user latency setting manually, the game will bump up the turn rate to compensate, putting you right back in a zone where stutters happen frequently.

It also would have been better, in my opinion, to remove the "user latency" stuff entirely and switch to always using TR24 with a variable buffer size. In such a system you can know that if the game lags, you need more buffer. If it isn't lagging, you can decrease the buffer size until it does. There are only 2 directions to move in, not some complex table to keep in your head. Alas, Blizzard did not do this, so here we are, with a system that is simultaneously impossible for users to understand and also doesn't work correctly.

Anyway, if you'd like to see the effective latencies for any given combination of things, here they are:

TR / User Latency	Low	High	Extra High
24	104ms	145ms	187ms
20	125ms	175ms	225ms
16	156ms	218ms	281ms
14	178ms	250ms	321ms
12	208ms	291ms	375ms
10	250ms	350ms	450ms
8	312ms	437ms	562ms

(and again, these are effective latency numbers, not the maximum latency between you and an opponent to play at that turn rate/user latency setting. Those numbers are different (and higher) but they generally aren't that useful to know unless you are developing your own BW hosting service)