Hey @eeriksp,
I have read the linked discussion but I would encourage you first explore other alternatives that iiuc could work in your scenario while keeping your snap under strict confinement. From your github documentation, I see the app “helps you to run predefined sets of commands in the server”: have you tried shipping the tools you need (e.g. stage-package) in your snap?
I also see you might need to run docker, so you could install the docker snap and then make use of the docker interface. This topic can be of help for further understanding Request for "classic" confinement for package Wilfred.
FYI, if you take a look at our process for reviewing classic confinement snaps, the need to launch arbitrary applications is not generally considered a supported use-case for classic confinement .
So I suggest you turn the snap to strict confinement again and try some of the options provided. You can use snappy-debug to alert you of any denials. snappy-debug will recommend interfaces based on the behavior it observes in your snap. Instructions on how to do so can be found here https://snapcraft.io/docs/debugging-building-snaps#heading--identifying-missing-interfaces