I am using Magisk 18.1 and root is working fine.I use Magisk Works good. I haven't tried v 19.0. I've been using 18.1. It should probably work as well though. Just can't say for sure.
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I also want to thank @spookcity138 for this great ROM!
We do have three S5minis in our family as daily driver.
This weekend I installed the first with the 20190310-version. The installation went almost fine.
I have only some (knows) problems with the ROM:
1. Recording videos: it is only working with footej camera, not with open camera, nor the stock camera. But even with footej using the camera sometimes crashes, especially while changing between camera and video modes.
2. Creating a second user with the multi user settings is not working. Every time I switched to the previously created new user the dialog to finish the creation of the new user crashed and I had to delete the second user.
3. I once tried to encrypt the complete phone. After the next reboot the phone remained in a bootloop and I had to wipe everything.