It's a tough one - there's so many variables it's hard to figure out what's causing what sometimes. The consensus seems to be that it's not the PG/VG ratios but the flavourings. I definitely find some juices (usually the darker, '
thicker' if that makes sense, ones) give cartos a hard time - I notice there's far less crackling noise when
vaping right from the start and if I've vaped them in a clearo, the taste is noticeably different. Dual coil cartos seem to help with them, as does upping the voltage if possible but as I prefer single coils and lower voltage/cooler vapour, I just move on tbh.
I generally go on sight - if the juice looks 'light' I give it a go and see. I haven't tried a huge amount of juices but M&Ps fruit flavours (red/blue ridge mist ect.) work like troopers in my cartos.