Mechmarket might be a good place to check
hisbaan
Catppuccin is excellent in terms of features, plugin support, and customizing highlight groups/palette colours
Convenience is often a tradeoff for power. Nobody is claiming that vi and its derivatives are convenient, they're saying it's powerful.
Personally I'm much much faster using neovim than I could be using something like vscode. There's a myriad of other benefits that modal text editing brings to the table, not having to use a mouse and constantly switch back and forth being a big one for me.
I find it much more convenient to press a button that's already under my thumb and then press a button that's already under my middle finger (for example) to get a symbol I want than move my hands from their typing position to get a symbol. It takes some time to adjust but I'm at about the same speed I was on a standard keyboard while using a corne (like the lily58 but with no numrow and one fewer thumb buttons per side)
Also space is right under your thumb as well, and shift can be in its normal place
It's technically a unibody split (notice that t and y are 2u apart) so that qualifies it as ergonomic according to the sidebar if I'm interpreting it correctly
I haven't fact checked this at all but apparently lowprokb.ca is working with Kailh on some choc v1 compatible silent switches which could potentially be used in those boards. Not sure when they'll be available though
Take a look at stuff from keeb.io, most of their split offerings can run with either side as the 'host' as far as I know
I'm able to sort communities by new, you just have to get the header to show up by scrolling a bit. It might be hidden if you have hide on scroll on
I think you might like the design of the typeractive.xyz corne where the put the battery under the MCU and have headers to give space for it
There are custom themes if you dig a little more in that menu
Before I sold my FC660C, I took it apart and lubed the sliders a few times with trybosis 3204. It was my first time taking apart a keyboard and wasn't particularly difficult and the stabilizer keys are really just wider regular topre keys. There is a wire, but it's inside the key instead of over top like cherry. A good set of tweezers is all you need. There's a good video by Taeha Types about lubing an HHKB which was not all that different. I'd say the most tedious thing about it was just how many screws there are holding the PCB to the plate
A few things to watch out for:
Feel free to reach out if you have any specific questions! :)