Wow, talk about an upgrade. That system should be amazing with such a large sump for flow. The other great news is that you have a massive refugium and "time out" spot for an aggressive fish if you need one.
Sure, if you want to risk shattering your tank. Honestly I don't see a single benefit to putting a mantis shrimp in a sump as the mantis won't get enough to eat and your refugium won't do much for you.