Feature Request: Expanding on Conditional Button Arguments

I'm not sure if there isn't already support for this functionality, but I couldn't find anything in the manual, so I figured I'd suggest it.

I realize there's currently functionality in place to support conditional arguments on buttons. (want vs need) What would be nice, however, if the ability to specify a sort of "default" value if no argument is given. For instance, something like:

{f!||s}

Or possibly,

{f!}||{s}

The second would probably be better so that you could do things like:

{f!}||%USERPROFILE%\Documents

At the moment, the only way I see to implement this sort of argument is through the use of a MSDOS Batch Function like: (Ignore my anal folder structuring and unnecessary batch localization)

@set cmdExec="%ProgramFiles(x86)%\Development\Text Utilities\Search & Replace Tools\PowerGREP3\PowerGREP.exe" /contextfolderrecurse @dirsonly @nofilenamequoting @runmode:hide @externalonly setlocal set TARGET={f!} if "%TARGET%x"=="x" set TARGET={s} @async:{$cmdExec} "%TARGET%" endlocal

It's definitely not a huge issue, but I figured I'd suggest it, more to see if there's an easier way to do this.