Actually I suspect they want a tablet that does all this automatically and in the background and integrated. So searching would literally find theb hand written text not some pipe line of exporting to a text file.
Yes exactly! I don't want my handwriting to be converted to text and displayed to me, just converted to text and stored in the background for searching.
Not an eink tablet, but Samsung Notes app on Samsung tablets do exactly this. It lets you search your handwriting without converting the handwriting into text first.