Can I change effect presets using Pattern Effect Commands?
Or how in general it is possible to automate change presets at effects?
Currently, no it is not yet possible to pick saved presets by using pattern effects commands.
But this feature is desired by many. It has a big chance to get implemented in the future.
you could go into the automation editor and initialize all the effects parameters, then go in another pattern, change to new/preferred preset in vst, and initialize all those parameters in the automation editor. Using vst’s with lots of parameters this can be a pain to set up, but it works.