Yes, I think having a bypass switch (perhaps a biased switch so you cannot accidently leave it bypassed) would be an interesting mod. I suspect that you could soon confirm that the processor was money well-spent.
The only
working Pye RT I had was the AM Vanguard, and I still have the mike from that. That was definitely under-modulated and I added a pre-amp on the modulator. Ah, the whine of the inverter, the smell of charging car-batteries
.
B