Straight key eh? Not the most popular CW key design these days but cool for a homemade approach.
Even plans to make an Arduino switch device. Cool.
https://experiments.withgoogle.com/morse-switch
I never looked into the documentation before, there are some Morse learning tools too
Discussion
They set a button for each, so it's kind of paddle-ish already. Could be a cool modern trainer.
Trainer I could see. The ergonomics of it made me shudder to look at a bit, but that sort of thing could be addressed without too much work with a 3d printer or even some woodworking I assume.
I have one of these. It's be pretty easy to wire those buttons to it.
https://cwmorse.us/products/red-double-paddle-with-steel-base