I guess a guarded Bat Master switch would be a good idea. Need to think why there is a gang switch over the Gens and the Bat Master, as a guard would complicate things there. I think the guard might get my vote. Worth more thought.
I think the reason you couldn't get the AP's back having done the airborne 're-boot' is that the standby AI will take about 136 secs or so to realign. Only once it is up and running will the APs re-engage. I think its all to do with AHRS voting. Just a thought not gospel. Maybe Geoffers might comment.
On guard you must be before you switch Masters. Align your energies or with manual skill you will engage your worst fears.
ATB
Red
PS Can anyone tell me what the consequences of deploying the floats with the gear down are? The drill for ditching does not require the gear to be lowered. Is this to aid the pilot with reduced work load or might the floats be damaged by the undercarriage in some way?