Is it possible to get the "Quickly open camera" gesture working with BOOX Palma?

I tried installing Secure Lockscreen Camera per the instructions here (only using Zygisk instead of Riru as recommended in the Riru README):

https://github.com/droserasprout/com...ckscreencamera

I've enabled "Double-Tap Power Button" under "Camera Gestures" in SystemUI Tuner:

https://github.com/zacharee/Tweaker

But am unable to get it working. I've tried Open Camera (preferred), and every apk of the latest GCam port listed as recommended in the README. The linked ANXCamera 404s.