I had a ReMarkable 2 last year, but sent it back. For reading PDFs my iPad Pro 12.9 inch is way better, and for taking notes and scribbling paper is way better. I can also have 10 sheets of paper or more next to each other on my desk, try that with a ReMarkable. It's a beautiful device, but inferior to the alternatives, at least for me.
You might wanna try Paperlike: https://paperlike.com/products/paperlike-for-ipad
It made a huge difference for me. My use case is similar to yours. I use it for drawing but also as an endless pile of paper with Concepts.
I have one :-) Never used it though, I just don't have a need for writing on my iPad. Writing on real paper with a nice pen is about as good as it gets for me.
I am always imagining how cool computer supported drawing or something like that might be, but so far there is no software for that which I like. When there is, I might finally use the paperlike!
