I actually wanna ad DE cause I had a problem with pests a couple weeks back. and oh man was it stressing me the fuck out. also silica is good for the plants, I've read.well put ShLuby!
I only use the crab, neam and DE in my top dress/mulch layer for pest prevention. works wonders. not much getting down to plants until after i recycle my mix. when the mulch and everything gets mixed back in for next round. this has worked for me,But as you said may not work for others. But i get away with not haveing to reammend until round 3 or 4. just fresh compost and airation each round.
does red wood contain tannin? not sure but i know you want to watch out for that stuff.
so with the 30 to 70 perlite to ewc and light top dress of mulch if it doesn't contain tannin.. lol how would I mix DE into that? like a heavy ring above all that. or mixed in to the perlite and ewc. or mixed with a light layer of mulch thay I will be top dressing with.