I had a weird experience. Before March 2020, I had less then 100 subs on Webtoons, after more than one year updating. Meanwhile, I had like 400~500 on Tapas. I did two things differently, though:
1) Every episode on Webtoons included 3 Tapas episodes, on average. So I had 3x more updates on Tapas.
2) I used to put that big ol' BL heart icon on the Tapas cover. Certainly attracted some people that would have ignored the comic on WT.
But then both of them decided to promote my comic during last year. Now I have twice more subs on Webtoons (5.3k) than on Tapas (2k) (and I also removed the BL icon before the promotions, it was making me cringe).
So I guess... While updating normally got me more subs on Tapas than WT, the promotion seems more affective on WT. I should try the BL icon on WT someday to test it, but I don't want 5k readers to see that now :'D I should have done this when I had less than 100...