Unfortunately the attachment replaces the vibration part you would insert, so unless the toy has some other vibrations it won’t vibrate.
In my experience its very hard to get false triggers like that. The pressure differences are very obvious for systems to track. My system uses a recent rolling average to work out an average pressure (like the nogasm) so its very clear when a true contraction comes long.
Once you have a sensor and a way to read it (I use Python), you can control a lot of things - I’ve used xtoys for vibes and restim for estim successfully. Keep an eye on Draak1’s approach - he’s creating alternative biometrics that look very promising.