There are other note apps that can sync with Nextcloud. I settled on Quillpad because of its checklist functionality, though admittedly it’s not perfect.

I’ve got a Keyboardio that has the main layer change key as one that you press with your palm. I’m glad it’s there, thumb keys are too precious to waste on that.

It took me about two weeks to get fully comfortable going from a normal keyboard to a Keyboardio. It was a long two weeks but I’m really glad I did it. And so are my fingers.

One Pi Zero 2W runs NodeRed to control a few lights in the house. Another used to run Octoprint until it recently stopped responding. I haven’t gotten around to troubleshooting it yet.

This isn’t a full answer to your question, but as for where secondhand keyboards are bought/sold, I bought one from eBay a while back.

I don’t understand the issues that prompted you to develop this, can you explain them a bit more? What hot-swap connector are you using this with?

Of course making a cool new board can simply be motivated be a desire to do so 😀.