This is indeed a deep rabbit hole. Creating your own can be pretty rewarding, but it's a massive time sink. I've made two so far, with a series of blog posts about one of them (https://bkienzle.com/posts/creating-a-custom-split-keyboard-...). This is my current daily driver: https://github.com/bkienzle3/zen_kb

I've been using this browser for several months now. I think it's the best option if you want access the addons that are available in Firefox for Android. However, the browser is definitely still beta. I often encounter bugs, mostly with tab behavior. These are still pretty manageable though, and worth the tradeoff to me.

I’ve been deep down the rabbit hole of custom mechanical keyboards for a few years now, and I’m now taking the plunge into designing my own PCB with KiCad. It’s been a very interesting project! It’s a split keyboard, inspired by the Sweep, but with 2 extra keys.