A single use FFP3 mask must be a complete seal so you have to be FIT tested using a hood and aerosols or there is a computer FIT test. If you arent FIT test it may be useless. A single use FFP3 mask must not be deformed so you cant push the mic into it. It only works for about 4 hours - written on the box - and provided it isnt wet.
Reusable FFP3 masks can be self tested because you can check you can create a vacuum. They are more comfortable. The filters last for weeks. The filters on the 7000 series from 3M are in a plastic casing and weather proof. BUT you must make sure the filter is classified as P3 - there are 7 different types of filter and P3 are in short supply. Using any other filter gives no protection...(a P2 will give the same as an ordinary surgical mask)
I have limited experience with a helmet mounted mask but I found it didnt provide a complete seal so useless for providing a viral barrier
The 3M 7000 series would be easy to mount a mic on the inside before sealing the plastic with sealant. I can easily make myself understood without shouting so an external boom mic may be OK and it doesnt matter of it touches the mask, but if anyone has used one with a standard mic I would be interested to hear.