I have an idea that could have made the sloth a habitat animal, but I'm not sure if it would have even been possible. I think you could have provided the players with different tree shelters. These trees could serve as enrichment items / shelters that sloths could interact with by climbing onto. The trees could also have a hollow where a pool of water could be stored. The tree could also provide leaves for the sloth to eat. That would mean all 3 of it's needs (shelter, food and hunger) could all be maintained with a single object, which would reduce the problem with the sloth being unable to reach it's needs in time due to it's speed. Zookeepers could restock the tree with fresh leaves and water whenever needed. Players could use multiple tree shelters inside their larger sloth enclosures to ensure the sloth always has a place to go if needed. That way it can wander around on the ground a little bit without getting too far away. Another way you could have done this is by giving the sloth a much reduced space requirement. Meaning that players could contain the sloth within a tight space if they wished to build a small enclosure. If the sloth had it's energy meter tweaked too it could get tired for longer so would spend more time in the tree shelters resting than on the ground wandering around (while it rested it wouldn't get thirsty or hungry as the shelter appeases those needs). I'll admit I'm not an expert on what you do, I'm just a person who plays your games so maybe what I'm suggesting is impossible.
I understand why you made it an exhibit animal, but I won't pretend I wasn't disappointed when I found out it wasn't going to be able to interact with the enclosure I wanted to build for it. When I heard about sloths in planet zoo, I immediately thought about the mangrove forest I wanted to build and I couldn't wait to see my sloths swimming around in the water. It was sad when I realized that wasn't going to be a thing because they won't interact with the environment I built. I generally play this game for the freedom and creativity aspect, it's fun to see animals interacting with the environments I build. It's not really fun to see them inside a box that was already prefabbed. I'd rather see the sloths hanging out in trees prefabbed for their needs, with occasional venturing on the ground for brief periods, than sloths on constant animation loops inside a box with prefabbed climbing frames.
On a final note. I understand sloths will spend a majority of their life in the jungle canopy when in the wild. They will however venture onto the ground when faced with no branches to travel across such as when roads are concerned. Considering this is a zoo and enclosures will not be jam packed full of thick tree vegetation I think it would be natural for the sloth to be venturing across the ground to travel from tree to tree or to new climbing frames. If a sloth ever found itself in a habitat where trees are spaced out I'm sure they would travel on the ground to get to new trees. It's just they come from habitats where there are dense canopies so never do that normally. Gibbons very rarely venture onto the ground either, but will do it when they have to (especially in captivity).