It's not easy to keep a track of phab task updates without watchlist. After much research and hit and trials, I somehow managed to navigate to subscribed task in mobile-view. (This was also quite a task)

But It was not sortable. It did not tell me which ones got updates.

Mail option floods email and I don't want my mail to be flooded.

Phabricator notifications are better but they can't be accessed in smartphone view once marked as read. Plus there's a limit on them.