Hello esperlad and PSS!
Progressive vibrato, open strings and sul ponticello are not included in Synchron Solo Strings.
@PSS: You can disregard the error message that you have posted. We have explained it in our tutorial.
https://www.vsl.info/en/tutorials/guides/dorico-integration/quickguide#installation
Please create a Vienna Assistant Support file and send it to us. Then we can take a closer look why Synchron Solo Strings and Synchron Percussion 3 are not displayed for you in the Dorico Wizard. Here's how you can create a support file.
https://www.vsl.info/en/tutorials/faqs/technical#va-support-file
Anyway, did you try what I have suggested and uncheck "Installed products only"? This way you can show and enable all libraries that we have Dorico settings for.
Best regards,
Andi
Vienna Symphonic Library