Set Initial Values in a form for 'Is part of' in Bridge Table

I have a map of Meters with a one-to-many relation to Meter Inspections and the Meter Inspections also have a many-to-many relation to Permits. From the map I can log an inspection for a meter and the meter inspection form already has the the meter relation set to the meter that I initiated the action from. The meter also has a dereference to the keys of the Permits. Now I am trying to set the meter inspection form reference to permits based on the the Meter[Permit_keys] so that I can add the many to many reference all at the same time prior to saving the new inspection entry.

I have attempted this via my custom action where I did the following:

Action is part of my meter table LINKTOFORM("LaramieCoMeterInspections_Form", "MeterInformation_fk", [_THISROW], "Related Permits", [_THISROW].[Permit_Keys])

The first part sets the meter relation to the inspection, the second part was supposed to set the (list) of values for the permits to this inspection. Unfortunately this does not work and I was hoping someone might have a solution. I have already set up an action on the meter inspection itself that executes a series of actions adding these relationships using ‘add a row to another table’ multiple times, but I would rather preset this relationship if possible. Any ideas?