There is indeed a phillips screw screw there, I haven't noticed it. It looks like it has a shimano-style cage mounting system with a pin holding it in place. I only had an experience with replacing sram cages that have a bolt on the inside of the outer plate that holds the cage in place so I was confused when I took ltwoo apart and saw a rivet in there.
Do you have a picture of the disassembled cage? I wonder if it's compatible with shimano since I'm eyeing some shimano compatible OSPW and it does not look like anyone tried it yet
Ill dig around for the pictures I took when I took it apart. It is similar to the shimano style pin, but, the spring holding section is different, not a one to one copy of shimano ones. Also, getting that screw out was a pain in the neck.
I had an old ospw from a 105 r7000 that I tried in it and couldn't get it to fit exactly but also I was rushing so I can trial run it this weekend to see if it will work this time. Just curious, were you able to make an account on the app to update your stuff..I never was able to.