

Having experimented with this a lot, I’d say it depends :P
Keyboard only you can get by with 5fps or so, but there’s no real feedback at that point.
15fps is ok and quite usable. Artifacts are the more annoying thing at that rate. 30fps is really more then necessary (though I agree higher is nice on lcd displays).
What bothered me most is the limited contrast, pixel density and limited amount of colors on color eink display.









There is a distinction between an app and a site. An application has many partial state updates. Two updates is uncommon for an app. Way different for a website where people ideally land on the right page from a search engine. There is a place for an SPA but it’s not everything.
We tend to stick with an SPA even for things which are mainly reads because we’re more efficient in a single tech stack. Sadly we don’t have big tech budgets to do everything. In theory the JS SPA backend can simply run in the backend if there’s no need for an SPA. I had thought hydration and caching to have gotten way better by now but there’s still a good way to go.