Whilst I have in the past advocated advancing the static TPS set up value of .64V I still had some very rare and occasional intake backfire I have totally cured the issue recently and below is what has worked for me.
I recently had my TPS sensor fail causing an erratic very low part throttle behavior where the TPS movement was jittering between 0 and 3% when pulling away or when cruising causing backfire running lean then rich and everything in between.
Upon replacing the TPS and doing the standard TPS/ISCV set up of .60V to .74V the TPS was lagging behind throttle movement by about 1-1.5% causing the dreaded intake backfire and rough running at very low throttle movement in the 1% to 3% TPS range. To correct this issue I have through trial and error manage to sync the smallest throttle movement with TPS movement.
My static setting for the TPS is now .66V and the ISCV setting is .78V I now have instant TPS movement as soon as the throttle (and RPM) starts to increase, therefore the low speed and cruise AFR is balanced and in sync with mapping, no more intake backfire and smooth transition when rolling on the throttle during coast and cruise.
Blipping the throttle results in an increase in RPM without the dreaded backfire.
I am not professing this is a fix for all but in my case it has cured the TPS lag and the resultant backfire.
A really important element to a smooth running engine is ensuring the throttles are balanced well - spend the time to match and balance the throttles your engine will respond well.