Yes, it makes sense. Targeting the group first had crossed my mind, but I wasn't connecting what $group_value = rwmb_meta( $group_id, [ 'object_type' => '' ] ); was doing... I had it there, I obviously had the variables named incorrectly. I just didn't put two and two together.
I'll keep it in mind for next time.
I can see how group can be useful, and I do know you can set a group to store variables however you want. That said, it would be nice if there was a layout option that behaved like a div that only dealt with layout in the editor and you didn't need to think about dimension when calling the custom fields.
Thank you for taking the time to figure out what I did wrong.
