Boom replacement

I'm thinking of finding or making a composite boom to replace my very heavy box section aluminum boom on my H21SE.
I know some hobies have been changed to boomless in later versions. I would like to know how the rig was modified.
I seems like most of the stress on the boom is in compression as the mainsheet blocks are attached right at the point where the clew is. A boomvang would change that but I don't use one. I have an old windsurfing mast I was thinking of using.
It would be great to have something with a lot less mass on those screaming reach jibes.
Any ideas or experience here?

It probably mostly depends on where the main block attach (as you pointed out). I know on the 18 the blocks connect forward of the sail's clew attachment point, so the boom is subject to bending forces. The Tigers just have a loop on the mainsail that the main blocks connect to. The boom passes through the loop with the outhaul lead back on the boom for adjustment, so all compression. Perhaps you could have a sailmaker stitch on a similar loop. Or, if you're open to having a custom sail made, a sailmaker could most likely design a completly boomless mainsail.

You might also be able to have a sailmaker stitch a section of bolt rope to the clew of the main and then use a boomlet like the 17 sport.

One of the challenges with using a windsurfing mast is going to be developing the gooseneck fitting (not impossible, but will take some thought and probably someone with a metal lathe). I would stay away from riveting into the composite boom unless you can get a backing plate on the inside. Composites generally don't like to have rivets in them.

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I figured I could simply imbed the goose neck hardware in epoxy and composite material.