Execute macro on import?

I have a macro that sets default values for some variables used by other macros in its group. That macro is activated at login. It just occurred to me after posting the macros that between the time someone imports the macro and the next time they login those variables won’t exist. Is there any way to execute a macro when a group is imported? In some ways this makes perfect sense; in other ways, it is too weird to consider. Suggestions? I suppose I can simply tell users to “Try” the macro to set those constants when they import the group.

You may want to consider something simpler and more reliable.
Have your main macro call the sub-macro that sets variables.

Probably overkill, but each macro in the group could have a conditional to execute that initial setup macro if it hasn't been done already. Here's two possibilities:

Execute the setup macro and then disable it when it's done:

Execute the setup macro any time a required variable is missing

Alternatively, i can test whether the variable exists and is not empty. I would put that in a separate macro, as suggested above by @JMichaelTX.

The problem with this is that I have 16 macros I’ll have to add this step to. good thing I don’t have 100.

This discussion was useful in another way: I realized that by executing the macro on login I would be overriding the user’s values next time KM started. (Apparently variable values survive KM restart.)