To be honest it's probably better off going into a pond basket or similar (or the ground) while you are doing any major development work.....I know how tempting it is to get trees into "proper" pots but I bet when you take a look at the roots they will need a fair bit of work which will come along far faster if they are in something appropriate for the job required. I'm a relative rookie myself but this spring I've moved quite a number of mine out of pots and into pond baskets as they just weren't ready.
Just my opinion though, in the end we all do our own thing
