I bought my iPad Pro 12" given the form factor in 2020. Here's my two cents on coding on it.
It's a brilliant form factor for writing. Get a Bluetooth keyboard and place the iPad vertically it's perfect to write with. I also hoped to code on it. I do connect to a raspberry pi to run Emacs. Coding on it depends on what you want to create. If it is backend servers, parsers, or anything that can be tested on your remote machine it works really well. The moment you want to do web development or create iOS apps you hit a wall. The form factor is great but the software is terrible for coding. Great for consuming, and occasionally for some productive work.
I had a similar experience. Mainly wanted to do stuff with R and LaTeX, and doing workarounds to view plots gets tired fast. Didn't help that my Mac Mini I was connecting to would often lose WiFi but not auto-reconnect (no wired option where I was living at the time). What's super depressing is my $80 Kindle Fire is a more capable device thanks to Termux+X11 server despite being multitudes slower as you can do everything on the device.
Maybe. IDK. I typically think of those as a Python thing and personally I was never very fond of jupyter notebooks so it's not something I thought of. For LaTeX I bought TeXpad which is okay but you sometimes needed to access their cloud servers to compile with certain packages. iPad is a very workaroundy workflow for coding.
It's a brilliant form factor for writing. Get a Bluetooth keyboard and place the iPad vertically it's perfect to write with. I also hoped to code on it. I do connect to a raspberry pi to run Emacs. Coding on it depends on what you want to create. If it is backend servers, parsers, or anything that can be tested on your remote machine it works really well. The moment you want to do web development or create iOS apps you hit a wall. The form factor is great but the software is terrible for coding. Great for consuming, and occasionally for some productive work.