The MegaPixel app won't come up using the PPPro. It does activate on the PPBeta.
I'm using Manjaro/Phosh Dev on both and update daily.
Appears to not be working on Arch either... had been working around 2 weeks ago
The version of Megapixels that Manjaro ships for the PPP is working (but the image quality is still bad, since there is no post-processing. Any picture i've taken so far had to be processed in darktable to get some color accuracy and contrast). Since i'm on Mobian i just downloaded the latest Manjaro-ppp image and mounted it to copy the config and binaries over to my ppp.
For myself, with daily updates from the unstable branch of Manjaro Plasma, the megapixels-ppp package must be installed in order to replace the megapixels package.
$ sudo pacman -S megapixels-ppp
But this is not sufficient at the moment. The device tree seems to need work.