Hi @svan,
You could do many things, but you can’t set on runtime as these are VM options to be set, way before you come into play…
But image you are working on a project and finally export it as ie executable, the runtime.options are included by build afterwards roll back.
Or a second approach could be to have a side by side processing installation, one for normal stuff and one for javafx which pointing to a separate preferences.txt (could be modified inside the processing dir, by the default properties file)
Cheers
— mnse