During the refit and repower I have eliminated the old CO system in favor of three separate Xintex Fireboy bottles, one per machinery space.

Option nr 1 is using a single Fireboy shut down module. I don’t like the idea of shutting down both engine and gensets for a discharge in single compartment

Option nr 2 would be to use three modules which is fine except for the price tag... over $1000.

Option nr 3 would be to use off the shelf relays for each bottle switch to trigger a shut down in the space it is installed. Setting up system ready and system discharged LEDs along with override switch is pretty easy

I wouldn’t do that on a commercial boat but on a strictly private vessel, why not?