You can ignore the gconf accesses. The mmap denial is almost certainly due to electron having an executable stack:
- Snap and executable stacks
- canvas.createContext("webgl") returns null in Electron
- AppArmor denial for /dev/nvidiactl
- https://bugs.launchpad.net/snapcraft/+bug/1739066
Note that Path for desktop launch "does not exist": Building from .deb has snapcraft.yaml that clears the execstack during the build.