Hi, Quest recentering (by holding Oculus button) should adjust the height and orientation to default (and the "seat" mode is the correct one for quest, that "room" will be hidden in the future, it was for SteamVR workaround). You can also further modify it in game settings though - head to SETTINGS, first tab PROFILE, and there's a Spawner height adjustment. The number is in centimeters, so if you would like to spawn the beats higher, enter something like 20-50 and it might help.
If you still experience issues please contact us at info@songbeater.com or visit our Discord server https://discord.gg/2cPXfwx, we'll be happy to help!