there are things that Android always tunnels through a VPN

Things that are NOT tunneled through the VPN, you mean.
A VPN is colloquially called a tunnel, so saying something “tunnels through” would mean that it does go through the VPN connection.

I’m lazy, and I already use Google Podcasts to keep track of what I’ve listened to already. Other than a client, I would also need to self-host something, so that I can continue my listening seamlessly (with synched progress) from multiple devices, including web browser on desktop, as I mentioned in a different comment.

If anything, I may consider a self-hosted solution like Audiobookshelf, as I need my progress to be synchronized across many devices, including desktop web browser, something Google Podcasts does well for me, in my opinion.

Not really, to be completely honest. I’m still too deep in the Google ecosystem.

I just use Google Podcasts.

I use 433 MHz buttons, switches and sensors for my smart home stuff, so I have a receiver (generic DVB-T SDR dongle) listening, and I can see all the tire pressure signals that passing cars send out.