anyone that comes here, there is some secret default that cloudways purges varnish every 4 hours. You need to ask them to turn that off if you are facing random cache flushes.

For anyone who comes here, this appears to be possible using the Cloudways API. Here is some documentation from CloudWays on how to create a script in PHP that accomplishes this. Their script could be triggered through a cron job, URL, SSH, or what have you. https://www.cloudways.com/blog/automatically-purging-varnish-cache-using-cloudways-api/

Just like you provided an option for NGINX STATIC CACHE EXPIRY to some xxx minutes in { Servers>>SETTINGS & PACKAGES >> Advanced }, Provide an option for auto purging or cache expiry for varnish
Thanks

Having the ability to purge the varnish cache on an application level would help. Sometimes we are required make changes to a specific website but those changes do not appear until the cache is cleared. The problem with clearing the cache is that it removes the cache for the rest of the applications.

Ability to purge the cache via command line. So I can create a script to automate purging. As it is a pain in the a** to keep logging in to my control panel every time I change a Magento 2 product description or update seo etc... which as you can imaging is multiple times a day!

Magento 2 has the ability to purge it for you automatically on product update in the backend, but I don't have the ability to edit the VCL file to configure this so I cant do this either.