I mean according to the readme compiling it is one command and it gives instructions on how to run. I don’t think monorepos really make sense for organisation purposes but I imagine it does work

Not that the raspberry pi is particularly low end anymore, but if you do want to run matrix on low end hardware you may want to avoid synapse as it is very resource heavy.

There are a couple implementations that support bridges here

Oracle cloud has a very generous free offer that i use that gives 4 arm cores and 24 gb of ram. I run about a dozen plugins including geyser and i never notice any slowdown and it never complains about missing ticks or anything. I only ever have about 4 people playing at the same time though

If you dont mind oracle then its a great option

Grep?