Hello Team,
I have seen all the posts and even android 10 Beta recruitment posts. So being a android developer and a beta tester for other brands too, i am shocked that there is no official guide from asus admins or mods which shows the users to how to downgrade back to android 9 stable from Android 10 beta. This should be the first thing which should be there in the forum's after you release the first beta.
I would request the asus team and mods or admins here to post a proper step by step guide regarding the same.