Limitations with Concatenate in Horizon Rules

I was taking a crack at building a rule using the Horizon Beta that would be adding a URL to a CTA linked object section using a transformation (concat) and upserting it to the custom object. I noticed that you can’t concatenate a GSID to a string with Horizon but you can in Bionic rules. I’m sure that I can make a work around but I was curious if anyone else was having this same issue or if there were plans to add this functionality in the future.