Nytrunner
Pop lugs, not drugs
I don't really want to go down as the safety naysayer, but....
We stage LPR rockets all the time without safety checks. It's not really any different to use a timer for 18 mm and 24 mm composite motors.
Valid, the safety risk is slightly less with lo-power rockets. (although @jlabrasca has some good graphics on the lethality or safety of model rockets and tissue damage)
I will draw a distinction though. Now we have 18mm composite motors. They don't stage immediately like direct/gap staged blackpowder, and they have a pressurization transient that can be different with each flight. Complication must be accounted for