Deleted member 5408779
I was on OxygenOS 9.5.8 and tried something today.
1. installed Magisk 19.4 Canary
2. installed Android Q DP4 via Updater app
3. flashed TWRP with Magisk
4. installed Magisk (inaktiv Slot)
5. Before reboot into system i rebooted into TWRP and checked if TWRP still works and it worked!
6. rebooted System and it booted successfully with magisk installed
TWRP is also avaliable but storage isnt supported. To flash something you need to do that via OTG.