If it's in a separate form factor, then you could wear them under a motorbike helmet
Not a motor bike rider myself. On the push bike, I don't bother with a helmet because I prefer full environmental awareness (and after 40 years on a bike, I ain't dead yet), though I could conceive of mountain biking situations where I'd wear one (if I did those thinks ; unlikely, as I don't like the mess mountain bikes make of high upland soils). when ice or rock climbing, I'll wear a helmet if I consider the rockfall hazard sufficient. And when caving, I need somewhere to clip my lamp(s), so I'm always wearing one. In short, neither a helmet-Nazi, nor a helmet-phobe.
But I'd be very, very careful of mounting hard objects inside a helmet - particularly in close proximity to the skull. I've seen the blood pissing out of someone's forehead because they put a lamp-mounting clip's bolt in bass-ackwards, and it ain't a pretty sight.
That's not saying that it can't be done - just that making it detachable for moving between helmets is going to require a lot of attention. I'd start by looking at fitting it around the jaw-line and cheek roots, for example. Smash them and you may well not suffer long term effects (apart from a smashed face), but do the same damage to your brain pan and you're likely to be ...
Any recent news on Schumacher? The last I heard was in mid-June and "slow progress".