Bougies are very resilient.
There's no problem taking a tree straight from ground to bonsai pot provided you can keep soil conditions stable until the new roots get going. We tend to use larger pots for collected trees to make it easier to maintain good soil conditions but also to get extra growth to speed up growth on any new branching. If neither of those factors worry you I can't see any problem.
If anything can cope with a smaller recovery pot, Bougies would be high on the list.
Just a reminder that trees dug from the ground seem to expand as you remove the soil. Your 2-3 inch trunk might end up at 3-4".
Another thing I've found is that the pot you thought would fit is invariably way too small. Even if you cut the main roots to 1 trunk diameter long that ends up at 3" trunk + 3" roots on all sides = 9" total width. Doesn't leave much margin for error or for growth so be prepared with something a bit bigger unless you feel confident to reduce thick roots to short stumps.