What's the use case? Is there a reason that the disk is not unlocked at boot/login?

I think any distro will do really. I'd go for something that is friendly to new users, if you're not very familiar with Linux in general. For example: Linux Mint. Here is an example on how you can get your installation setup easily: https://www.youtube.com/watch?v=IyT4wfz5ZMg

Regarding your Valve Index. It will likely work, but don't expect it to be very easy to get it running well. I'm currently on Arch Linux with red team hardware and a Valve Index. For example, you will need to ensure the udev rules are set properly: https://github.com/ValveSoftware/steam-devices. New issues occasionally arise, see: https://github.com/ValveSoftware/SteamVR-for-Linux/issues. Currently, it's not switching audio devices automatically, so I use pavucontrol (with PipeWire) to switch that manually.

I think Wikipedia is a valuable common good and should be maintained. Because I can afford it, I donate monthly, even if I only use it a few times each month.

Arkenfox its documentation is great. When I first found out about it I was blown away on how much one can do in order to improve their online privacy.

Firefox with strict settings is pretty good as a baseline. Arkenfox takes it to a new level.