I just duplicated my issue. Setting lower than 24/48K introduces lag <EDIT: when re-enabling Atmos> (audio behind video). It also disables Atmos. And setting higher (I tried 24/192 and 32/192) disables Atmos.I've never noticed any sound lag and I put it at the max. I've never had any issues with the oversampling on any of my dacs except one which would bug out unless I kept it to 24bit, instead of 32bit. But other than that one, never had any issues.
Set it to the max and see if you hear ANYTHING remotely off. I certainly don't.
Since I use the Hel 2 only for gaming (always with Atmos) and general PC use (YouTube, etc.), leaving it at 24/48K isn't an issue for me. Without Atmos, I could set it higher as you suggest. That's why I qualified my statement with "If you're using it for VSS".
In the midst of me trying to figure this out a month ago, I asked you via DM if you had ever experienced latency with your Hel 2. I finally figured out it was an Atmos thing.