TL;DR: transmute farming sucks, and transmute farmers make the dungeon experience worse. To fix both issues, transmute crystal rewards from RND and maybe from BGs should be a significantly larger amount once per day per account instead of once per day per character.
As someone who has a bunch of builds in the works for my various characters, I'm constantly running out of transmute crystals, and farming them by doing RNDs on all my characters sucks and takes a long time. Additionally, transmute farmers make the dungeon experience worse by being fake tanks, fake healers, or speedrunners who run ahead of the group and straight to the bosses while pulling all the trash mobs.
In general, I feel like I shouldn't have to do 5 dungeons across 5 characters just to get the 50 transmute crystals to change the trait on a single piece of gear.
I think a good solution to this would be to make the transmute reward from RND a much higher amount, and only give them once per day per account instead of once per day per character (while keeping the exp rewards etc. once per day per character), something like 100 transmutes once per day. This would make farming transmutes significantly less of a hassle, and I think it would also result in less fake tanks, fake healers, speedrunners, etc., because there would be less people doing their tenth RND of the day and just wanting to get through it ASAP. Therefore, it would improve the general experience of farming transmutes, and also improve the dungeon experience as a whole. However, this could result in longer dungeon queue times, but maybe not as long as the gold/exp rewards are still per character.
Alternatively, BGs could also be made to only give transmutes once per day per account and then have RND and BGs both give something like 50 transmute crystals. This way you can still just do an RND and a BG on your main to get your 100 transmutes for the day, which might also result in more people doing BGs and lower BG queue times.