@XanderBakker
Is it possible to symbolize (in Pro) a layer using an Arcade expression with a 1:M related view table?
Here's one of the Arcade expressions I am using for the layer's pop-up configuration (in Pro) to show the related customer and their assigned device (i.e. can type)... Hoping I can use/modify this expression to create symbology based on whether a customer has a device or no device (i.e. Gray for none assigned and green for device assigned).

Thanks,
Don