Gimbal lock happens at tilt = (+/-)90, at which changing pan and roll has the same effect.

In terms of ambiguities, the main concern is tilt. If, for example, your tilt gets to 180 and your roll gets to 180, even though the entity looks like it's oriented upright it'll tilt down when you want it to tilt up and it'll face away from targets when you try to face towards them.

In practice, keeping pan and roll between -180 .. 180 is just as "safe" as using 0 .. 360, but is slightly easier to maintain since you can take advantage of the ang() function to enforce it.

Jibb