We used to have seeking, but it mostly meant having to manage the
position pointer inside the uxntal, it's not something I actively need
right now so the implementation probably won't come from me, but I'm
not opposed to it if we can fit it nicely within the current File API.
What application are you working on that needs seeking?

The way collapseOS handles something like seeking is to work with
multiple files, each a page of memory, and using the filename as
makeshift seeking address, this might be an option for you, possibly?

https://github.com/schierlm/collapseos-uxn