I agree. I've been using Wireguard for about 6 months now. The quick start is great for getting a quick overview but it doesn't really document properly how a configuration file should be made.
There is no real detail about how a wg-quick config differs from a wg one, and they're not compatible; it'll complain about unknown keys/values or something if you use a wg-quick config with extra firewall rules and the like with plain wg.
I also saw nothing anywhere about how if you modify your config file and down/up with wg-quick it'll delete anything you entered in your config as the 'down' will write back the current state of the interface. It's not a big deal, but it messes with the usual workflow of editing the config file of a service (you don't want to down it while updating your config, which could take time).
otherwise, wg has been great, it is generally quite reliable on Android but I'd like to see an easier way of doing the exclusions, inverse CIDRs are not my forte.