Looks promising

There's an API to get all servers and current capacity -
https://www.ipvanish.com/api/servers.geojson - and ovpn files are all available directly - https://www.ipvanish.com/software/configs/ (ca crt looks to also be here).
From the
support information, it looks like VPN unlimited has some kind of an app that generates the ovpn file... I can't see direct downloads anywhere. Is that correct?
You're not overthinking it at all

Once generated, it is just an ovpn file but all the contents of it would need to be hardcoded in the script because (without using their API) it's not possible to get the configuration automatically. It would certainly be possible to automate this from an example ovpn file but this would need to be maintained manually if the provider changed anything... and if there is anything specific to the user generated through the API, it will only work for the user who provides the example file.