I can see the potential in your tagging system, and I like it! The PWA is solid, and it's fast, too. Kudos.
I'll have a review written up shortly.

I've read your responses to questions regarding workspaces, and this is the only sticking point for me.
I'd really like a more robust way of separating my work tags, and my personal tags. Currently, if I'm using Bookmark Manager on the weekend to save something personal, I have to sift through an ever growing number of work related tags. The same applies vice versa.
While I understand that I can simply start typing for a tag, that requires that I remember the tag exists in the first place. I clearly defined list of my personal tags, and of my work tags, as separate (or seperatable) entities would really help me use your product 24/7/365.

If not workspaces, perhaps we could have the possibility of hierarchical parent tags? (ie, if an entity has parent tag X: 'personal', for instance, then only suggest children of X)

Thanks!