I thought I couldn’t do any root work in the fall?
To clarify, I wouldn’t do much to it until you know the root system can respond well to major work to the top of the tree. I re-pot stewartia grown in nursery mix as the bud scales shift to “actually” open. The bud scales slowly flare a little for last half of winter, so it’s easy to think they are waking up during February on in most climates I’d imagine. My stewartia were grown in ground in North Georgia, and weren’t irrigated for most of their life. Big roots formed @ base in trees’ search for water, but not always in scale for a future bonsai. So, I gauged the two old root locations.
Depending on how long preparing root system for bonsai will take, heavy reductions to canopy may need to wait. It could be fine to chop and repot next spring; can’t tell. There could be a clay blob inside the nursery mix and and woven basket of roots.