I'm drinking now LOL. I usually use 24mg diluted down to 12mg (realized it was too strong...). Like you, I chainvape when I've got a few liquorhols down. So, currently, my PV is welded to my face

.
Anyway, I had a brain-fart moment (maybe it was laziness?) and topped off my cart with some full strength 24mg. OMG the headrush. Granted, you're asking about only a 25% increase instead of a 50% in nicotine. I really didn't feel like draining out the cart, so I just dealt with it.
All in all. The whole cart wouldn't have been the full 24mg the whole way
through and I didn't use it for a entire drinking session but it's been over an hour now, no problems, the nico high only lasted about 5 minutes and I've managed to almost suck dry my cart...this time I'll remember to use the diluted stuff...I hope
Hope this helps somewhat ^^.