I don't know if this is any help, but when I had my L6 in me 2wd sapphy I had the exact same problem a fluffy spot just above idle when driving, very rarely it was 100% clean but mostly hesitant when trickling through traffic.
I measured my tps with ignition ON, done all the tests, done the sweep as slowly as possible, could not detect a duff section anywhere, got annoyed after 45 mins or so of trying, it seemed to be totally linear, so adjusted the tps all one way and went for a drive, position of hesitancy had moved, confirming to me it was the tps at fault, I can only surmise that it is due to the very low current passed by the digi metre that it couldn't be picked up.
All back together thought no more of it, though the fluffy spot reared it's ugly head when I went to emerald K3, it was a dead as a dodo spot, couldn't even drive through it with zero load on the rollers, it was chronic, fitted one of daves(£20) universal tps aligned with ecu, 2 minute job, to dial it in, then was mapped perfectly.
It just goes to show the L6 was shoving so much fuel in it was effectively masking the issue, this would later be born out by economy afterwards, curiously the problem on the L6 wasn't apparent on the rollers as a particular problem.
If you have a new one I would just try that, all I do is fit the tps, leaving a few mm gap so it is not fully home, rotate it a bit let it spring back tighten down.
The tps inside has a low setting contact, adjusted by allen screw so should read a minimum anyway, that's how I did mine, was always near enough.
tabetha