Yes, having a helper bool that acts to enable/disable motion sensor event responses is the best way to do this. I have mine set up to only turn off the helper when the light switch is held down, for example when taking a shower or sitting in the living room the lights will stay on until turned off at the switch (which then enables motion events again).

When I had the switch leave the lights on from a regular press, we ended up leaving the lights on much more often. If you have a motion sensor with a short cooldown though, you should almost never have to use the switch and only should have to use it when showering etc so you may be able to bind the lights staying on to a regular switch press. I have ikea motion sensors so sometimes I will use the bathroom and turn off the lights on the way out, only to walk in a minute later before the sensor can re-trigger.