going to check for intake leak again, thought “trusted shop” had also checked for this, BUT...l just finished switching out the loud slash “race pipes” with stock mufflers l found on CL, and discovered the gasket in the front head pretty much gone with the flange nuts only finger tight, and the rear gasket about 75% gone. So lm pretty sure there was a sig exhaust leak, and less sure about the trusted bike shop that couldn’t find anything.
After replacing pipes, respraying/soaking IAC, inside throttle body w carb cleaner and a quick test ride last night, the idle still a little rough/wonky w occ backfires, which could be remains cleaner residue, but weather was cold w heavy fog so engine didn’t realy get hot enough to do more than burn off the surface brake free id liberally used to take exhaust apart.

Initial performance now much improved, rpm slows pretty much as expected when throttle off, low speed performance much better, can now idle down steep curving roads smoothly in first at 15 - 20 mph, drive in parking lots w/o bike farting, wanting to stall or accelerate, as well as at higher speed on freeways.
Also checked out trouble codes as per another thread, and found one for the IAC p0505 displayed among other numbers not noted on the thread l’d referenced on how to do it.
plan for next couple of days is to investigate the codes more, will post results.
fair winds

Turned out to be an intake leak, apparently the seals were just soft enough to seal when the engine temp was low, but when temp increased like on a hard run, the seals would leak untill the motor cooled down. Irritating that l tried spraying several times w carb cleaner and still missed it.

thanks all for the advice