You definitely have some points, but I was just trying to offer an alternative view, or just playing devil's advocate.
I use several high-gain amps. If I need a volume boost, I personally use a compressor, which works well. Distortion and/or overdrive pedals act a lot like boost pedals when the drive is set
While there may not be many pedals that handle line-levels, almost every rack delay I've seen does. Very few amps, regardless of brand or cost or quality, very rarely run effects loops at true line levels. It doesn't make any sense to, since it wouldn't allow the use of almost all pedals, thereby decreasing the usability and perceived value of the amp.
You're right, the range of level control added to V3 could do more than simply balance levels, and I wouldn't complain if Eventide added the ability to control the level via ext switch, MIDI CC, or exp pedal. On the other hand, the TF is a delay pedal, not a gain pedal.
You could always rearrange your presets, using the preset map in the utility function, so that you wouldn't have to change banks (unless you wanted three or more levels of the same effect).
And, hey, if all else fails, blame the sound guy, right?? They never remember to turn up the solos. 😉