@jnbrgr
Us adding extension support on mobile independently is a rather unfeasible task. It's one thing to implement it, but maintaining support Chromium update after Chromium update would likely be a near impossible task.
Out of curiosity, which extensions would you like to use in Vivaldi on Android?
@Vivaldi Thank you for your answer.
Requested mobile browser add-ons would be Bitwarden, uBlock Origin (built-in functions in Vivaldi don't work as well) and Privacy Badger.
As long as you have Bitwarden's app on mobile, it does work with Vivaldi as well.
As for the Tracker and Ad Blocker, have you looked into adding more custom blocker lists to it? Our community has been sharing some lists on https://forum.vivaldi.net/topic/45703/share-blocking-sources that you can try.