Keep in mind the wot a/f ratios were fairly decent on both the QFT carbs when they made their best runs.
So, whatever you do to lean out the part throttle cruise, you're trying to do something that changes that part of the carbs operation by around 3 points......and have essentially zero affect on wot operation.

There are smarter guys with carbs than me, but I have a feeling it's easier said than done.

The QFT 1.52 carb had the least offensive part throttle cruise operation when it was first bolted on.......low/mid-12's, with the 80/90 jets.
However, with that set up, the motor didn't take a load real well, and I aborted the run about 800rpm into it when I saw the a/f ratios weren't getting out of the 15's.

Once the jetting was increased to get the wot a/f ratios in line, and the power up......which ended up being 88/98....... then the part throttle cruise was down at the bottom of the 11's.

The Demon had the next best part throttle operation, low-12's, and had the best throttle response.
IMO, this carb is probably the best candidate of what we ran to be tweaked to get decent part throttle operation for street use.
The down side of this carb as we ran it was, it had the biggest change in wot a/f operation from the bottom of the run to the top........it really richened up at the top end.