Scriber on rotary plasma cutter

I am fitting a scriber to my plasma cutter that is designed to do flat sheet and rotary or tube cutting. I am mounting the scriber on the floating head of the torch in order for me to do a touchoff probe with the scriber. The scriber is dropped into position with a pneumatic cylinder with a 45mm travel and then once the scribing starts I will lock the floating head with another small cylinder.

Does this sound feasible or is there a better way of doing this?