If you’ve cut back the foliage heavily a few weeks ago, I would not be messing with the roots now. It’s just gone through a massive change and will be in all new push-mode to produce a new entire flush of growth all over the tree. I wouldn’t be touching the roots, as you’ll completely throw the tree into chaos so soon after a heavy cutback.
Most Lepto varieties I have root-pruned have been pretty hardy. I’ve happily removed 3/4 of the roots off of nursery material with no dramas. The key is to do it when the tree is healthy and bushy and growing strong, like mid or late spring, but it all depends on your location. Neil and many experts are like Superman when it comes to root removal, in that they go super hard for great success, and they have a tonne of material to repot. Provided the tree survives, it is much wiser to go hard initially. I sometimes don’t have the courage that they do, and probably stick with a 50% root removal on my older material. But they will get better results quicker. My results will take longer. But if it’s a first attempt, you might as well go somewhat hard, because you don’t want to spend years on the root reduction slowly over time only to discover the roots are a nightmare in tight. And this can often lead to root rot and other problems, which is why the best approach is to go hard initially and concentrate more on separating the roots at the first instance rather than the mindset of reduce, reduce, reduce.
But having said that, I have many Leptospermum brachyandrum that I have removed probably 80-85% of the roots at the first root prune, and had no dramas. From experience, Leptos will probably drop all leaves if the root prune was too much for the remaining foliage. But they’ll usually shoot all over from the trunk in 3-4 weeks or so.
Having said that however, there are species of Lepto you would not attempt a 3/4 root reduction with however. But even my hardiest Leptos, I wouldn’t do a root prune so soon after removing most of the foliage like on yours.
Lepto don’t seem to be bothered so much by having wet feet. But not constantly wet. But after a root prune, the best care is to make sure you water again when the tree needs it. It will significantly reduce the water uptake, so when you do finally do a root prune, remember to just monitor it and water it when it gets dryish but not bone dry. But in the first 3 weeks after a root prune, DO NOT let the roots dry out.
….. oh and one more thing.
From my experience with Leptospermum, their roots are highly susceptible to damage from a strong jet spray with the hose. The roots easily get stripped and will die off if your hoses jet stream is too strong. You can do this on the outer areas fine, but when you get in close and work your way inwards, reduce the strength and spend more time physically separating them. There’s nothing worse than spending an hour reducing the roots, to then quickly rush the most important part and have it stripped of the outer protective layer.