Slow HEAD request to large file info to files end point

I need to get the last commit date for a file. I can do this calling:

{{gitlabUrl}}/projects/{{repoId}}/repository/files/{{fileName}}.txt?ref=master

and then using the last commit id to call the commits endpoint. For small files it’s fast however it slows down the larger the file. By the time I request information for a 50MB file (we can argue the merits of a file this large in git I know) it take about 6 seconds to come back.

It’s a lot quicker than making the same request as a GET (that’s about 15 seconds) but it’s still slow.

Is there a way to make the above endpoint (or the blame endpoint) quicker on the HEAD call or, another way to get the latest commit id/change date for a file?

Thanks