Are There Plan Limitations on Customizing Smart Cart for New Rebuy Merchants?

Hi just checking in, it’s been a minute since I’ve worked with a new merchant who is using Rebuy and don’t already have things established but are there plan limitations if we’re using Smart Cart with how much we can customize it? They said their cart is “minimally configured” so I’m not sure if that’s because the plan is limited or what but following up with them on some other things there so wanted to make sure I understood the ins and outs of that (please feel free to point to docs I may have missed).