Final bump:
Due to a combination of factors, I stayed with my gut and went with the M7.
The P78 Pro was tempting, and I wanted to switch to it, but cancelling aliexpress orders is a pain - and realistically, since I read close to my face without my glasses on due to a -7 prescription, this is probably the best answer - the buttons seem nice for night reading too.
Sage was out of the running (though it was hard to make that choice) as even though they're cheap and nice I need Tachiyomi.
I'll be returning later with a detailed review later, as details on these are SCANT. I'd like to shoutout a particular channel in this regard, for any readers:
Sherry.
Around 600 subscribers, they have good neutral lighting and actually show off feature sets and even updates unlike the only alternative - Good E-Reader, who aren't *low* on info, but I prefer this format.