Replacing my Inkpad 4

Hi!

Didn't post in a long time, although i am an old-timer here. My journey with ebook readers included:
Rocket Ebook
Sony PRS-505
Pocketbook 360
...
...
Inkpad 4
XTEINK V3

i do like my Inkpad 4 from a hardware perspective, it's a great piece of tech. But the software is ... well, mediocre.

I really liked the Kobo Sage, but couldn't live with the battery life.
I don't care much about display options, all my books are being worked on in calibre (stripped of all unnecessary things and adapted to my style)

So here are my must haves:
- at least 7"
- warm front light (good quality)
- modern eink display
- no color
- usable as left handed
- shelf support through calibre
- series support through calibre
- filtering options (Pocketbook cannot hide read books!)
- only needs epub support, i dont care about pdf's
- Instapaper support


Nice to have:
- reading statistics

I might go with the BooX Go 7, but i am not sure, how good the library functionality is.
Is it working well with series? Does it support shelves? can i filter read books, by start date, etc. Does it support Instapaper? How much of a difference is between 7" and 8"