As far as I've been able to gather from the forums it is not possible to use a custom Shoutcast URL on the HD Mini 2 other than the ones listed under Internet Media / SHOUTcast Radio.

Since this prevents me from using my paid subscription on DI.fm, I was wondering if anyone has looked into possible workarounds.

Since it is possible to store favorite Shoutcast stations, would it be possible to edit the file containing those favorites (after probably first decoding it, as I expect it to be an .rss file) and manually insert a station identifier somewhere with the authenticated URL to the service I subscribe for?

Would it otherwise be possible to, for example, achieve a connection from placing an m3u or pls file on my NAS and use that as a starting point to a Shoutcast server?

A bit of tinkering on the filesystem is no problem, but any starters would be welcome!

I am afraid this is not possible with the current firmware. Maybe you want to try to check out our development section - i think you get better help there:
viewforum.php?f=98

Sorry but i cannot help you with this as this is not officially supported by the device.

cheers,