Alright then. I thought we would need a server cron service to work as trigger for your plugin? My plugin idea was to fake such a trigger, to make it trigger on what is happening in the panel or the site, that then for example could trigger your plugin to run. But maybe you have it built in?
Anyway, I don’t like the look of the image thing, looks too hacky for my taste. To trigger it from the site I think a better approach would be to use something similar to https://github.com/jenstornell/kirby-starthook or just on load by the custom plugin.