ah, I see.
If you want to modify the footer based on email or country or something, then a snippet will be fine. The challenge is if you want to modify the URL params on the snippet, you can try a few things:
- set the url params once in the snippet...but this doesnt solve the problem
- if you must set new params for every email, you can tokenize this at the program or folder level and make the change for each program.