All I can say is that a game company - a big one - already uses it internally to produce their macOS builds on Windows (it reminds me that they talked to me about something some time ago regarding all this, I should contact them to know what the idea became...)
FYI this year the toolchain's code signer gained the ability to code sign *and* timestamp macOS apps. Because of that new feature, notarization is also doable from Windows now.