Older .grc files (3.7) at GRC 3.9

I've found a problem when pulling 3.7 grc files into GRC on 3.9.
Command-line parameters of type "string" get converted into type
"None", and thus don't end up as actual command-line parameters.

Is there a tool for doing smooth transition, other than manually pulling
in to GRC, turning those parameters back into String type, and
saving the resulting file?