I came across the Alphasmart and normally would've jumped right on it, but what I didn't mention in the OP is that I travel a lot (and for long stretches when I do), so I'm trying to keep my load minimal.
Since I already carry an e-reader (Kindle 10th gen in this case), it's worth it to add a 6oz folding bluetooth keyboard to my pack for the ability to write outdoors. A 2+lb Alphasmart, however, is another story.
That said, I found the Likebook Air
on Aliexpress and it looks like it might be exactly what I want — an e-reader and e-writer in one. If it is, then it'll replace the Kindle in my pack and bring me one step closer to leaving my laptop behind completely.