Awesome - definitely getting there.
Make your cloth attachment weaker, so that it can deviate from the fat a bit. (something like 2 x 104)
Just to confirm, the source of the cloth attachment is is the cloth itself right? You only want to attach the vertices of the cloth to the outer vertices of the fat. Easiest way to do that is select the cloth first, fat second.
Same goes for the inside of the fat. Select the fascia first, then the fat. Because it's a closest point lookup, only the inside of the fat will be attached. I'm sure you're already doing this, just wanted to double check š
Try reducing the bend stiffness on the cloth, and even increasing the stiffness of the fat underneath. Will just require playing around at this point to see where you can get to.
The zSolver locator should roughly be the same size as your tiger. (because they're a little over a meter tall) Is that the case?