With the use of run when not in a directory next to the Runfile, it would be nice to have a convenient way to make paths relative to the primary Runfile.

It's possible to do this already, but it's awkward in that it requires shell code, and it needs to be duplicated into each step that requires it, e.g:

deploy-reviewer:
    RUNFILEDIR=$(dirname "${RUNFILE}")
    cd "${RUNFILEDIR}/foo"
    # ... actually do useful things

If, instead, we could do this, IMHO it becomes quite a bit nicer with many different commands:

EXPORT RUNFILEDIR := ${.RUNFILEDIR}

deploy-reviewer:
    cd "${RUNFILEDIR}/foo"
    # ... actually do useful things

On the subject of attributes, with includes being a thing now, it might also be convenient to have attributes for the paths relevant for the imported Runfile, to be able to more easily make reusable things. The included Runfile may be in many directories all over the place, and want to make use of some resources right next to it: the included Runfile is in a better position to be able to define where that is, than the primary Runfile is, in my opinion.

This can be split off to a separate issue, if preferred.