So I did some research to find out why my villagers took a while to change professions. Villagers will try to path find to every workstation in a certain radius. The more workstations near the villager the longer it will take. Solution is pretty simple but annoying to do, you have to cycle through professions away from any workstations. Unfortunately there is nothing you can do other than to remove every workstation or do it far away. Its a problem with Minecraft that Mojang has to fix not the server.
this is strange, because i usually role librarians all near each other with tons of lecterns and they change fairly quick, though if you have traded with them before they wont change professions
I think it’s mainly trapping the villagers. As in not letting them have a way out as you change their professions, if there is a pathway to an open / unclaimed trade’s block they will autopath towards there. However if there are no pathways to any unclaimed trade block they will remain where they are until you offer them an unclaimed trade block.
After you find a trade u want, u can lock in the villager by trading, then u can destroy the trade block and move it whereever you please. Thou not sure what would happen to the villager if they are without a trade block by the end of the day, they may go unemployed.
Safari eggs are a good plus, or if you already have a place for them to stay.
However if you do not lock your villager’s trade (aka give exp) the safari egg will keep it, but once u let go of the villager they will immediately lose the profession or change their trade.