There are a few things you can do to get it stiff again. I will avoid the obvious jokes...

First, you need to look at the tightness of the tramp. You want the tramp tight, very tight. Enough that the side bars of the tramp deflect about and inch or so in the middle. You can do this by pre-deflecting the side bars before you lace the tramp. Again, there are plenty of posts in both forums on this subject

Second, you need to check out the pylon to casting joints. You want these tight. Some are already tight and others have lots of slop in them. If they are sloppy you will need to shim or glue them. I prefer shimming because it can easily be undone. I don't like permanant "fixes" for this problem. There are plenty of posts on this forum and the Hobiecat website forum about shimming and gluing these joints.

One thing to be wary of is the bolts that hold the pylons in the corner castings. Don't overtighten these. The bolts tightness does not affect the rigidity of the boat. They are only used to keep the pylons from falling out of the castings. If you over tighten them, you can crack the castings. ($$$) What you want to see is a snug fit between the through holes and the bolts. This will help eliminate any slop in these joints.

I hope this helps.