I vape Bobas in Boge's in a J Tank punching 2 holes with a saddle valve and initial fill of the carto I use a syringe. Just dripping Bobas in a carto takes forever to wick down due to the thickness. Topping off I can't say since since I have only used Bobas in a carto with a tank. 2 holes or slots on a carto with thicker juice or 50% or higher VG is needed for good wicking in a tank set up.
Cheers...
If you dont use tanks etc, try some Smoktech cartos. I use the Ressurector cartos, which are the Smoktech 1.7ohm XL cartos, with Bobas and have been using the same carto for a over a week. Granted I normally get 2-3 weeks with 80/20 thinner juices, but its still not bad. Smoktech cartos filler is wrapped looser than most other cartos and works pretty well with higher VG juices
the only way i vape boba's is dripping on a lr atty around 4.2v...it hits that perfect spot for me
everything else i use a boge lr carto
The best way to vape any juice if you're looking for flavor is dripping an atty. (Hat tip to Boneshark and Huffelpuff). IMO, if you haven't dripped it, you don't even know what it really tastes like.