Disclaimer: Not a Kobo employee; don't have deep knowledge of their product line; just own and happily use a couple.
The Elipsa 2E is very nice for large format reading and note taking. I bought it recently and compared it to other options from Boox and reMarkable. I ended up with it because I already had and enjoyed my Libra 2, and "like the Libra 2 but bigger and with a stylus" was appealing.
That said, if I wanted something for your use case, I'd probably start with the Sage. The short version is it's a Libra 2 with a stylus, and that seems like it'd be a good combo.
Somewhat related, I tried some non-electronic options for such things before, like a Rocketbook. Clever idea but I didn't like the implementation at all. Its OCR couldn't deal with my handwriting at all. I now have 2 distinctly separate note taking systems:
- My Elipsa 2E for writing down meeting notes (while avoiding the distractions of an iPad or laptop, which is important for me personally but other people might not care about at all).
- A paper journal (Traveler's Notebook) I take everywhere and use for my personal thoughts.
- I lied. Number 3: "hey Siri, remind me ..." for capturing ideas while I'm out and about, and then I follow up with them when I get home. That works so well with AirPods, too. If I have an idea while I'm out jogging, I can ask Siri to remind me about it without breaking stride. First time I did that it felt like Star Trek.