Okay, well gear lever lets you add command line arguments which get saved in the config so that should work easily. I will say it's odd to me that you say this is needed for a specific OS, let alone often. I have never used that flag and I've been using an Ubuntu variant for ~5 years now. Doesn't mean you're wrong or anything, I'm just surprised because that seems to defeat one of the main purposes of appImages. The whole security/safety model seems to be sidestepped if you use that flag. I tend to only use appImage if it's my only option because flatpaks seem to work better in my experience.