After that you can have a mostly normal desktop experience w/ the addition of a tablet. How long can a person stare at a screen that's only six inches?
So, ultimately I'd suggest using a tablet and [mini]keyboard with the phone as a hotspot instead; unless you're a die-hard masochist. Of course it's a slippery slope and a full laptop might be ideal for most users.
Phone displays are just too small.
> I've been wanting to build something in this space.
Did you have something specific in mind?