aoe2de://[match ID] can be used to launch AOE2DE, and deep link you into a match’s lobby. Is there a way to deep link into spectating the match instead? Perhaps a different URL scheme (e.g. aoe2de-spectate://[Match ID]) or parameter (e.g. aoe2de://[match ID]?spec=true)?
Yes, the url-scheme you are looking for is: aoe2de://1/[match ID]
I also tried these variants of the “/1/” segment: 0, 2, 3, [none]
But only the “/1/” succeeded in spectating the match. So I guess “/1/” equates to “try to spectate the match with the id in the next url-segment”.
PS. If for some reason the url-helper does not launch from your browser, you can also run it manually, by opening the windows command prompt (cmd.exe), then running (with the quotes preserved): “C:\Program Files (x86)\AOE URL Helper\AOEURLHelper.exe” “aoe2de://1/[match id]”