Perpetual mulled cider?

I brought mulled cider in a crockpot to a party, and after it was finished the host kept adding more (not mulled, just straight from the container) cider as it ran low, leaving in the cheesecloth of whole spices and the orange slices (and putting the crockpot temp on high). It seemed to work ok, though the later batches were not as flavorful as the original.

Curious if anyone has tried this or has any tips? It seemed to heat up decently fast so I don’t think there’s a food safety concern here, but curious if there’s any ideas on getting the spices in the later batches. Like should I bring a second cheesecloth of spices and/or orange to add in later?

Also just to be clear, the title says “perpetual”, but this was just over the course of one night, not like a long term thing.

And for anyone curious, here’s the specific recipe I used: https://recipekeeperonline.com/recipe/grRY2_JB7U-8SHPFKhVY8g