OK, a follow up to my one spring change.
After a 70 mile Enduro yesterday I can attest that what I felt was better compliance on the small stuff, with a slight loss of whoop stability (wants to hobby horse).
I put one .40 in with the stock .43 for an average rate of .415. Much easier to pick lines into turns. If there is twisting, unequal flex, etc. I can't feel it.
Any suggestions to stop the hobby horsing? Guess I need to recheck the sag (may be high as a consequence of lowering the front with the softer spring rate) and maybe slow the rear rebound a tad as it feels too active. At a reset I tried more front compression but then my wrists took a pounding and it resisted turning in as well. Didn't have time to soften the rear compression, but would I soften hi or low to level out the bike? Too many questions.