I can only comment on using the EFEST PURPLE IMR 18650 2100 mah FLAT TOP 30Athat fits my caravela fine,It's a pretty tight fit so not sure a button top would fit
I didn't need to do any filing with mine but then I've only used the caravela style genesis atty and a mini protank2 using an ego adapter,Both have a fairly deep recessed connector
So I might need to file it when I change atties