

Thanks for linking that. Reading the paper, it looks like the majority of the “self-host” population they’re capturing is people who have a WordPress site. By my reading, the wording of the paper would disqualify a wordpress.com-hosted site as “self-hosted”. But I’d be very suspicious of their methodology and would expect that quite a few people who use WP-hosted reported as self-hosted because the language is pretty confusing.

Set your expectations: networking is complex and the configuration you’re hoping for is particularly complex. It sounds to me like you’re looking for a split-horizon configuration where local traffic stays local but internet traffic is routed over VPN. But also you want that configuration only for specific apps.
It’s not the *arr programs that are tricky, it’s that any service you try to configure this way will be some of the hardest sysadmin work.