Set Pins_Allowed Property for Padstack Keepout

I want to set the property "Pins_Allowed = True" for a keepout that was defined in a padstack as opposed to one drawn in a board file. I can't figure out how to make this happen - is this possible or do I need to do this a different way? More specifically, I can't select the keepout shape associated with the padstack as I could with a keepout defined in the board file directly; this would allow me to edit properties and allow pins, thus removing DRCs. I can of course just waive the DRCs but that feels like a poor answer to a problem I created.

For context: We have a multi-layer board that requires antipad regions in our ground planes to maintain signal integrity. Depending on the position of any given ground layer relative to the signal in question, we need antipads of differing dimensions. For setting up the simulations that determined these dimensions, I manually created route keepouts and placed them by hand on each ground plane, setting the appropriate properties to avoid DRCs. This successfully pulled the copper back from the signals.

Since I have to do this across many signals in various configurations, I wanted to edit the design padstack to add these shapes in automatically. I chose to do this with keepouts as opposed to antipads since a) keepouts are visible while antipads are not, thus I can confirm that my shape is applied correctly and b) I was having multiple overlapping issues with antipad clearances that were conflicting with settings I needed for other aspects of the design. I've successfully been able to create custom shapes and use them as keepouts and antipads.

Thank you!