Gday Gwilks
I don't know the Catfisher 32 too well but they are a solid cat. For all the cats I know of and have seen launched and slipped, all of them can be slipped under the armpits or the hulls. In fact it is usually better to go under the armpits.
If you are worried about the
boat not being able to handle the strain then don't. If a cat can't take the load of the hulls being suspended then you don't want to go sailing on that cat. Just make sure that the bridgedeck is flat, that you can locate your main strength bulkheads and that the
trailer rests gently on the bridgedeck at these points.
Try not to rest the boat's weight on protrusions or lightweight fairings on the bridegdeck. For example some Schionnings use bridgedeck stiffeneres made from PVC pipe covered in glass. Don't let the slipway put the weight on structures like these. You want the weight to be fed from the floor of the bridgedeck and then into a bulkhead.
cheers
Phil