Not burning. I had an issue with Koolada making my throat sticky and making me cough. I’m still upset about it. LOL.
Not to butt in, but an ltrasonic won’t assist you in physically shaking and mixing the nicotine up. later once it’s mixed it will help steep it further. I think your idea with either a larger bottle ( make sure your storing in appropriate temperature areas like cool drawer or dark cabinet and try to put your nic in glass if it’s a large amount) and shaking it so it has the extra room will do the trick.
Also, since it seems it could be a plethora of issues that could od gone wrong maybe try switching your base to a 100% VG just get a smaller 120 ml bottle that way you could break it down to two 60mls and you may could shake them easier. If it comes to it get a small warm bowl of water place your nic bottle in there for a good 10-15 minutes then shake it this will help loosen it up. Or build a contraption then patent it lol bc we’ll all want to buy it! ( OMG edited this phone is terrible today) didn’t meant to cuss it was the phones fault!
glad to hear your on the mend !!!