Only thing a bit buggy is xmr wallet sync, it wants to resync from 0 every time I unlock but common (yet unsolved) issue with web thing. Absolutely seamless once caught up and does not clobber my profile.
Discussion
When you say restore from 0, are you saying 0 monero block height or the block height saved from when the wallet was created in nosmero?
If you are using an incognito tab that would explain why the delta sync isn't working.
Using regular browser tabs, nosmero saves sync heights to localstorage so unlocking is from last sync instead from start height.
Let me know if it is something else you are seeing, thanks