cheapino VS Skeleton-Dactyl-Mini

The cheapino is super cheap: https://github.com/tompi/cheapino

If you're looking for a 40s Ergo Split, then the Cheapino is really cheap: https://github.com/tompi/cheapino/ (though you have to source parts & PCB yourself + soldering required)

Is there a project similar to the cheapino with a similar goal of offering a DIY cost-effective monoblock 34/36 key keyboard?

inspired by the cheapino

Depending on how comfortable you are ordering PCBs yourself, the Cantor (https://github.com/diepala/cantor ) or the Cheapino (https://github.com/tompi/cheapino ) might be a good starting point for getting into split keyboards, both are diodeless, so you only need to solder the switches and use relatively cheap microcontrollers

If money is a big concern, you could look for cheaper style boards like this one designed specifically to be on the cheaper side: https://github.com/tompi/cheapino

Here is the link to the project: https://github.com/tompi/cheapino

If you have access to a 3D printer, I would recommend handwiring a Skeletyl or Scylla.

if you are looking for a sculpted/keywell design I would start with something like the https://github.com/sanderboer/chonkybois or https://github.com/Bastardkb/Skeletyl then work on refining your needs from those ideas.

There's these made by Quentin, which can be mirrored for Skeletyl/Cnano.

Awesome. Do you think single-key RGB would be an issue? Would it add too many cables? I'm currently looking at the Skeletyl, but am intimidated by the four additional cables per LED.

If you have access to a 3d printer you could print something like a skeletyl or a dactyl manuform and then handwire it with some diodes and wires. That's the cheapest way I can think of.

I'd throw BastardKBs Keyboards into the mix as well as he's open sourcing all of his designs, for instance the Skeletyl or the Charybdis

You can take a look at the Skeletyl. It's a 5x3+3 design. Basically the upper three thumb keys of the one you posted and with 2 keys less on row 3 and 4.

a printed, blue Skeletyl