With 2 cradles the problem is not so much where the cradles are, but whether the bow and stern are supported.
Puget's point is a good one. The longer length of the TI requires bow and stern support. I had always had a bow support but I noticed hull deflection just aft of the rear cradle caused by an unsupported stern. After trialling blocks, rollers etc I found adding a third cradle at the stern to be the most effective. It supports the main hull stern in storage/transport but allows for much easier loading/unloading by supporting all of the TI's underhull when sliding it on/off.