Yep. Since it's meant to stop people from inhaling it, it's probably not good to spray it into vaping gear.
I build computers and stopped using canned air many years ago because it was just too expensive as I was going through at least 3 or 4 cans a week.
Now I use a rechargeable Coleman Quickpump I picked up at Walmart for about $30. Trim the little square piece off the cone attachment and it works great both for blowing out computers and vaping accessories. Just keep it clean so you aren't blowing dust around (or rig up an air filter on the intake) and it works great. I've had mine for about 4 years now and it's still going which has saved me thousands on canned air with no additives to worry about.
Sounds like a nice way to mod one. I go through a can every couple of months doing this and that. I doubt the bitterant is harmful or it would defeat the purpose but no sense in taking in anything extra. I've got compressors but just use the cans for simple chores around the house like blowing out my guns if they get sandy and my keyboard once in a while. Not so much now that I don't dump ashes down it lol.