Stewartia nursery stock

Hi, I acquired a Stewartia Psuedocamillia over the weekend from a local nursery… it is currently in a 3gal pot, about 5ft tall, and has new buds on the end of each branch but not leafed out. My understanding is that they bloom towards the end of June.

I am wondering about the general timing of events regarding the development of this tree. i know I need to reduce the root mass but i also need to do a trunk chop and prune back the branches to increase ramification/refinement. Is it best to do the repot now and save the branch/trunk work until later in the year (late summer or fall) or do everything now before it fully leafs out?
thanks, Any insight would be greatly appreciated…