I've been logging some runs near stock limiter with the UTEC and I'm seeing the throttle closing about 5% towards the top of the RPM band while the pedal is still to the floor. Is the TS reflash the only way to remedy this?

Here's a text log.

[RPM][MAF][TPS][LOD][KN][IGN][WBO2][TAFR]
6350 5.0 100 100 0 31.0 12.92 12.80
6550 4.9 100 100 0 31.5 12.91 12.80
6673 4.9 95 100 0 32.1 12.87 12.80
6790 4.9 95 100 0 32.8 12.83 12.80

Yes it is

With E-manage, & UTEC can't you tune it not to close since you can program the actual parameters

The throttle is not controlled by the E-manage or UTEC, sadly.

reflash is the only way i believe.