might there be a list of integrateds that allow you to disconnect the preamp from the amp section via jumpers?There may be but that feature isn't really HT Bypass.
The purpose of HT Bypass is to turn an integrated amp into a power amp with the push of just one button and controls its volume from the a remote surround processor. Bypassing the integrated's preamp section. And then go back to the integrated's preamp by pushing the same button again when playing a source connected to the integrated.
No changing cables each time you need to use a different preamp but want to use the integrated's power amp section full time.