If it's any help, I emailed with Frank recently about HT bypass and he made it clear that his preamps and integrated could do HT bypass using the tape input and output.
I guess maybe I am confused about this.
First of all, I was under the understanding that the Left & Right main channel outputs of your home theater reciever or processor should pass though the preamp unaltered on the way to the Left & Right main channels of your amplifier, in an HT bypass set up? The preamp signal is not back fed from the preamp to the HT receiver or processor and then to the amp. The classic reasoning is that the stereo preamp will have the better fidelity for classic 2 channel operation than the HT receiver or Processor, or you need more analog inputs that the HT receiver or Processor has.
As far as using the record input & output for HT pass through, that may work for psuedo HT pass through, assuming the tape in jack receives from from the HT receiver or processor and the tape output feeds the main left & right amp channels, but under this scheme you will also have to run a second set of cables to your same left right amp channels for the variable volume output of sources connected to your preamp.
My thinking was that a true HT bypass input simply routed the signal from the HT receiver or processor directly to the preamp outputs when selected and by cable on the the main left & right channels of your amp, without any alteration or preamp volume control affect. (In other words preamp volume control is bypassed). But signals from all input sources connected to the preamp, (HT reciever or processor, turntable, CD player, DAC, transporter, etc), left the preamp by the same output jacks going to the amp.
If I am confused about this, somebody enlighten me.