Item drop probabilities on raids may need adjustment.

Not "challenging" in that it's difficult to do. Challenging as in shifting resources around to spend the time to make that change. The time to make the changes for this idea is not insignificant. We have to balance that against other changes players want and continuing to expand the game.
In some cases it would be "easy" as for the last bunch of expansions (It would take research, more of that valuable time, to get an accurate number... so will just say "bunch" for now...) we make a single script that all raids run to give that type of reward. It's when we hit raids before we started that convention where it is individual per raid, and changes will need to be made to scripts created by different designers of varying skills and uses of different coding styles and habits :/ And lots of them. Maybe we also convert them to use the current system, but that only reduces the time required slightly as the majority of the time will be finding and interpreting the individual "reward" and/or "Success" scripts. (In many older cases this may be a separate script but buried within the scripts that run the event)

Yeah. And that makes it more difficult/time consuming because we have to include additional coding to account for progression servers.

This is only a comment on the feasibility and no commitment to any changes

On the subject of raid trophies:

1. Can we have one placed into the Achievement system?
2. Continue to have a different trophy on the end game mob each expansion?
3. Expand the number of raid trophies we can have active at one time?

Trophy of Talendor when will you drop Some one said oh it used to drop 1/3 of the time not see it once yet -darn random.

and Magelo has no drop info you would think if its a chest or body or some thing it would show up
https://eq.magelo.com/item/128787

chest drop, used to be body but the body poofed on death.

drooped a hero`s satchel tonight