Meleagris have about 50 percent chance of transitioning. A lot can make or break it.I have a Meleagris leopard, is this one that will transition without being pushed? When you say you introduce new fish, do you mean any fish, or specifically another species of leopard wrasse?
If you add a fairy or flasher to a female fairy or flasher that is equal competition for a spot on the pecking order then it will most of the time transition quick.
Can be done with sand sleepers but more hit and miss. Any fish can have same effect on some wrasse and mix of wrasse can have same effect but harder to size them up. Smaller unnatural Qt tanks seem to make some start to transition but can’t say for sure. A lot of mine and others in qt setting I see wrasse transition. Stress and mix of wrasse in small area maybe idk.
Fish will eat more when pecking order is being pushed to grow big and strong. That is when they transition.