Because installing /e/ overwrites the recovery partitions
And besides, please don’t flash TWRP to your device, just boot it with fastboot boot twrp.img
What problems do you have with the usual way, it apparently still works
Edit: To be slightly more precise, since you are flashing your whole phone anyway, you can just take the boot.img from the /e/ release, patch that with Magisk and flash it to your device. If you need help with that, please head over to the root topic
