When it comes to something like Node, TypeScript and Angular the lines between what is considered the server and the client become a little more blurred and the development model shifts quite a bit from what we are traditionally used to. When supporting cross-platform devices the architecture makes all the difference.
It took me quite a bit to wrap my head around how to refactor my Angular mobile apps, but after a bit it started to make more sense to me. There is nothing to say that Epicor couldn’t allow EFX like functions shipped as part of the client min and you can use those in AppStudio.
I would recommend just for kicks build yourself a mobile app that uses Epicor REST as your endpoint. We basically rebuilt MES in a mobile app for our maintenance guys to use on tablets and I have to tell you it’s pretty glorious. And aside from displaying stuff on the screen, it doesn’t have a ton of logic in it that falls outside what TypeScript natively handles for rules and events. We specifically set out to build it using Kendo (Kinetics base) to get a feel for what we might be in for. Just build something small and it might become clearer how the approach will be different but you can still yield the results you desire.