Hopefully this should prove useful to some, I've created a tool to run Gallery Apps from inside designer. Best thing is you can use it to schedule gallery apps that require parameters via interface tools, including Alteryx Connect loaders.
Sorry about that. It was built with what I thought was an SDK compatible with 11.7 but it seems not. Looks like there was a breaking change in the Initialisation stage of the SDK code. Are you able to upgrade to 2018.1?