I think I probably know the answer already, but perhaps someone can either help, or give a knowledgeable "no".
I've been using git-p4 to work on a Perforce depot (syncing, editing, submitting) for a long time, on the main branch. I now want to work in a stream. I tried using all the git-p4 options for branches (the docs don't mention streams but I'm trying to treat them the same). I also tried just doing a git p4 clone //depot/streamname but that tells me No changes to import! and quits instantly.
I found two projects that are forks of git-p4 to support streams, each a few years old, and each unable to submit back to the depot, so they're no good.
I can't change to use branches instead of streams, as the rest of the team want to use streams, and supporting my unusual workflow isn't a good reason to change (even if I am in charge!).
Is there really no option available other than actually using Perforce here? I hate it with a passion, and I would much much rather use git (or anything else!).
Not sure about git-p4, but you could use Git Fusion to enable you to work with the streams.
This is not a client side product like Git-P4, so if you have multiple Git Users who want to work with streams of depot paths, they can take advantage of it.
More details about using it with streams are here: https://www.perforce.com/perforce/doc.current/manuals/git-fusion/#Git-Fusion/section_j4q_gtx_nm.html%3FTocPath%3DSetting%2520up%2520repos%7C_____11