Mattbonsai

Hi Guys, I have an Acer Dissectum that I worked on last year, and even though it was only last year I worked on it, I think its ready for a bonsai pot, but, its in full leaf...

Would I get away with repotting it now (Mid-spring), or do I have to wait until winter? This tree is beautiful, and needs repotting soon (I couldnt in winter due to time restrictions and distance away from tree).

Any ideas?

Cheers

-Matt-

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