I decided that a small super-compact relay bypass board might be a good thing to have in the toolkit.
Does anyone else think that an opto-isolated control for the bypass function might be useful in addition to a switch contact as shown below?
The LED input side would essentially be a current loop input permitting logic level interfacing over a wide range of voltages and ground references as well as providing galvanic isolation.
The "Passerby" Balanced Passive Bypass board.