Can a patch define with which options it should be started?

Hello,

I don’t suppose there is a way to make a patch automatically start with the right vvvv options by double-clicking on it?

I mean, could the patch xml contain the information ‘I am a patch that will only work if vvvv is started with /dx9ex’ for example?

not possible.
you’d have to make a batch file that runs vvvv with /dx9ex and opens the patch.