Hey @SeanMcC
Thanks for asking the Community another great question.
Just to make sure I am understanding correctly, you want to add a custom profile property through your browse abandonment flow of the brand of product they were looking at? With browse abandonment flows, customers can move through them many times so you may not need to back populate if they return to your site and create another viewed product metric that will trigger your flow with the custom profile property.
Please let me know if I didn’t really understand what you are trying to accomplish!