How to support adaptive power management better?

The game I am working on sometimes performs badly under adaptive power management with vsync enabled - the gpu is dropping down to 340Mhz instead of 790-1020+ that it usually does.

This means it can’t hold 60fps on my game. If I lock into maximum power management, I get steady 60fps, but at 340Mhz I get just over 16ms, so it locks to 30fps.

I think part of the problem is that the game is fixed timedelta, so if the gpu can’t do 60fps then the game has to run the logic twice. This causes the CPU to bottleneck at >16ms, so the gpu now thinks it is doing fine running at 30fps because the CPU is the real bottleneck (presumably because there is so much idle time between when SwapBuffers is called and the next VSync).

Is there any way I can hint to the drivers that I need more performance out of them, even though it LOOKS like I don’t? Many customers just assume because other games run fine, it must be the game, not some graphics setting, so they don’t seek advice - they just chuck a bad rating down and move on.

I should add - I am running a GTX 660 Ti (GK104) on 64bit Windows 10
Drivers WHQL

Though we’ve had the problem on other specs.