Rule wise - If it is properly rated (not china fake) and the games rules do not specify full seal, that I don't see an issue with it. It would be your judgement call on weather the gap is too much for you or not.
If this is to mitigate fogging while having facepro, this will definitely not work well at all though. It is going to be fog city once you start doing anything more than a brisk walk. Gonna capture all that moisture.