The point of these lectures is mostly not to teach how to work with Turing machines, it is to understand the theoretical limits of computers. The Turing machine is just a simple to describe and well-studied tool used to explore that.

For example, are there things there that cannot be computed on a computer, no matter for how long it computes? What about if the computer is able to make guesses along the way, can it compute more? Because of this comic, no — it would only be a lot faster.

Arguably, many programmers can do their job even without knowing any of that. But it certainly helps with seeing the big picture.

So far I have had good experience with kopia. But it is definitly less battle-tested than the other alternatives and I do not use it for too critical stuff yet.

As others said, Synapse can sometimes be very resource-hungry. It might be worth giving a try to Conduit and Dendrite, which are alternative Matrix server implementations and especially Conduit seems to be focused to by lightweight. Although I do not have any personal experience with them and it seems that they are most likely a lot less mature than Synapse at the moment.

Also see pairdrop, it is a snapdrop fork that allows connecting devices on different networks using a numeric code and has other improvements.