Normally, you’d want to give collections a bit of time to properly recover... this ensures NOT ONLY that their health can compensate the work, but also that you don’t put a bunch of work into something that is .. “CTD”..
The “rule of thumb” that I’ve heard tossed around is one growing season of recovery...
That being said.. I, personally, begin work halfway through that “recovery season” if an ABUNDANCE or “surplus” of vigor and health is noted..
So I guess basically, my answer is.... ONLY “work”/perform procedures on healthy trees...... and in the immediate spring following collection.. it is going to be difficult to assess FULL health... so this is probably why everyone will say.. “wait a year”...
Important to differentiate... on coniferous/certain evergreen species.. this rule (One insult per year)DOES stand MOSTLY solid. I have wood ashes to prove it.