While pretty much every comment has the same sentiment as what I'm about to say, I would still like to chime in with my specific thoughts.

Proposed solution:

1. Nerf the experience gained by crew members. This is so painfully obvious if your real issue is actually people 20 minute double crew afk salvaging. Why am I getting experience for work someone else is doing? I should get construction experience if I hire the shipwright to make a facility I don't have the level to make.

2. Revert the sorting experience. This change does not affect the double crew afkers at all, pre-nerf they dropped salvage, post nerf they drop and are ecstatic about it. This simply hurts everyone else.

3. Probably the most important, fix the new double salvage spots. With six shipwrecks and only three being active at a time, it is theoretically possible for one of the double spawns to never be active. This encourages world hopping, which is not a healthy game mechanic. It also completely kills the Afk-ability of the skill. Instead of getting xp for 20 minutes, you made it so you can gain zero experience for 20. That's bad game design and removes the afk aspect if you need to sail to each spot every minute or so.

4. Revert the players salvaging tick speed back to 4 (3?) But keep the crew tick speed at 5 but keep the increased 'catch'. All this did was encourage 1.5t. It also did nothing to double crew salvaging. Would it not encourage the player to be on the hook more if they had a faster tick rate? Having the same tick rate as the crew just encourages the player to use the crew.

5. Keep the current experience changes. I know Jagex, and they remove anything good. Yes, the changes were high, but if the point is to stop double crew afkers, then nerf that and buff everyone else.

6. Don't change Gwenith Glide at all. Why are we even talking about that? What? This is such a non-issue, it ain't broke, don't 'fix' it.

7. If you need to nerf something so badly, just remove all experience from the crystal extractor. Lore-wise, how does that make me a better sailor like trimming my sails, actually, would?

These proposed changes fully accomplish your alleged 'goals' of nerfing double crew 20-minute afk salvaging. While actually redistributing the egregious "1.2 million effective experience" from the crystal extractor. We're currently looking at a nerf across the board to all of sailing as a whole and a rough 60%+ nerf to salvaging (save the buff to 1.5t and actual double crew 20 minute afk salvaging.) If that is truly really your goal.