This is very much not true - if you have unsigned executables for an app of any scale, 3rd party AV will be extremely Unkind to your app, especially if you try to do updates. Also, how long your app gets blocked depends on how many downloads you get, if your app is popular it can be unblocked in a matter of hours, and once a download URL is deemed trusted, this is largely a non-problem.
Also, while I'll 100% agree that CAs on Windows are a nightmare, the tooling is extremely straightforward, signtool.exe takes your cert file, a password, and an executable, then signs it.