No, I wasn’t part of the design team. Nowhere near creative enough.
I like the current design of the ToL. It keeps the benefits of the two or three (?) copies I’ve seen in the 2e materials.
I especially like the maturation of trees of life gains them more protection. 
Plus, I like that the terrain (for spell’s save DC and caster level) is treated as abundant. It gives a little oomph for preservers, above and beyond protecting fertile ground.
It would be nice to add the 4e zone of max healing from spells. I don’t know what a “square” is, in terms of distance in 4e, but they have a 5 square (5×5 squares?) aura. And I don’t know how the mechanic translates, but spending an extended rest (sleeping 8 hours?) in the aura grants an extra healing surge (whatever that means).
Also, performing a divination ritual in the aura grants a +5 bonus to a skill check. (Also don’t know what that means.)
These latter two benefits seem to replace the four daily spells available to clerics and druids, though, so I can see ignoring them.
The spells I’d like to see added to a variant tree of life are Backlash (Wizard 2nd level) and Conservation (Wizard 3rd level). A minor sting (5d6+5 max, save for half) to warn defilers. If they persist, they can’t cast (save negates). Even if they save, the terrain is treated as barren for determining spell’s save DC and caster level.
After which, the usual tree of life protection kicks in.
These would obviously be rare (because most trees of life would be found in defilers’ groves). It might be a fun adventure to try to infiltrate SM’s groves to try to “install a patch,” though I think that would be counterproductive (they’d just raze the grove and start over… or not bother with groves).
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