Wow thanks for all the replies
For the smaller meals more frequently we were thinking about it but I'm not sure we could be consistent with meal time in that case (our schedule varies a lot). Right now we feed him at 8 ish and at 4:30 ish because that's what works best for us to make sure he has some down time before and after meals (because we are worried about bloat).
For the actual ways to slow him down I really like the idea of using the muffin tin I never thought of that! I will give that a try tonight and see if it works out, if not we will try something else.