To maintain a fair comparison, GitHub has supported self-hosted runners for several years (maybe that doesn’t work for your specific usage, for whatever reason).
Tangentially related, when I was on the rowing team in college the coxswain commonly replaced ‘seven’ (the only two syllable number in the 1-10 range) with ‘save’, to maintain a smooth cadence for counting 10 strokes.
You can see my first build (blue) in several of these pictures following similar advice to OP's guide (looping diodes, etc), with one modification where I used copper tape for the columns instead of wires.
Then the first picture you can see how much cleaner the single-switch PCB ends up, and I can assure it was far easier to solder / strip / assemble.
There are certain kinds of fully custom keyboards, such as the one I use (Dactyl Manuform) where the keys do not sit on a single flat plane. Such a build would require a flexible PCB. This is doable for the advanced-amateur EE but the geometry is fiddly, at best, and doesn't allow for easy experimentation on key placement (spacing, offset, radius, etc, the bigger problem for me).
I've found the happy medium with single-switch PCBs ("Amoeba" is a popular one), which are fast and easy to wire up. Most notably you don't have to do the painstaking row wire stripping -- just use a plain wire from one PCB to the next in the key matrix (or an insulated wire if you have to traverse other components, which still only requires two stripped ends).
I have a few pictures floating around from my build(s) if that interests anyone.
(I'm not the parent commenter), but I believe a defining quality of a senior developer is someone who I can give any problem/project to in the business domain and they return with a solution in the technical domain.