would it be wise to use v5.10 pragma?

In my opinion it is always wise to add a version declaration. I add it for the version I'm developing for. Or, more precise, for the oldest version I'm going to run tests for. So, for standalone scripts this would always be a fairly recent version, and 5.10 would only appear if I'm contributing to an application which says it needs "5.10 or newer".

So, in your case I would recommend to include a version pragma, but probably not use 5.010;.