Idle speed delay & stepper adjustment

I'm still fighting with idle speed problems and rough throttle on my 990SD with no 2nd flyes, MH and custom map

I had some problems with low idle last year, then I replaced the throttle bodies (used) and the bike had worked good until I got the bad idea of making a throttle body alignment
Since that I had noticed a rough throttle behaviour that makes it really hard to handle at low range and low speed
Along with that the idle has a strange delay before leveling, when riding goes around 2000rpm, but when you stop or on the side stand decreases to 1500
I tried to adjust the little nut on the stepper motor (with no fookin' reference!) and I noticed that this adjustment impacts only on the "stationary" idle speed, but on the run it's 2000rpm as before

I cleaned all the cleanble wiring, swapped the stepper motor and the TPS with the old ones
I've lost count of the "reset adaptions" and 15 min reset
In all this time I never saw a single error code on the tune ECU

I changed the rectifier with the upgrade model 2 years ago. The battery has 6 or 7 years but works good, being always connected to the battery charger.
just miss a start sometimes.

The city dealer don't want to take the bike with all the mods
many friends are telling me to bring the bike to stock, but it's a bullshit. It worked good for one year and thousands km with all the mods! And it was great!

Wtf I should do to have my SD back?

Check the intake rubbers for air leaks from poor seating, damage, etc.

Done
I checked the values from tune ECU
I also swapped them and double checked

thanks No.47

Clutch switch?

I was going to write it, checked that too ^^
I did all the "normal" checks
I was wondering if anyone had specific experience on the idle delay or on the stepper adjustment

'Fraid not - how did you balance the TB?

Yesterday I rode the bike to the dealer (12km) and it worked a little better than I remembered, it seems the problem of idle delay appears only when the engine is warm
Dealer's mechanic tried the bike quite well, saying it's not going so bad
He told me that in his opinion the bike is running lean ad low rpm, under 3000rpm

Can this theory explain the tendency to run bad and grumpy at low rpm? Also the high idle?
Why the custom map that worked fine for a year has suddenly become lean after the throttle body replcement and balance?

What the fook can I try in the only day left before leaving for the trip?