First you say it's impossible to build to minimum weight without an autoclave and pre-preg carbon ....but in reality almost all the builders are building at or within 5 kg of minimum weight using standard building practices
Second to make them light they will be too expensive… over 30K...but in reality they are being built and sold for reasonable prices, a little more than half of what you claim... and the one who is using the most carbon in his boats is actually one of the best priced…

Third...now you want to make them heavier because a light cat takes too much effort to keep moving....on the water…

Can we just jump past all the "death by a thousand cuts" comments and go straight to its logical conclusion.
Which is...just forget sailing altogether and rent a (heaven forbid don't buy..they might come out with a newer/better model by the end of the year...you can't have the guy anchored up next to you having more cup holders than you have) Party Barge (outboard powered pontoon boat) You have a couch to lay out on, a big cooler for your alcohol beverages and a canopy to keep you in the shade. No sails to worry about just turn the key and go. It doesn't matter how fast or heavy it is cause you’re only going to the sandbar anyway...no need for the after race party...why waste the time sailing ...it’s a party all day....
There problem solved...now wasn't that easy?
All those who want a heavier F16 can go the party barge route and the F16 Sailors/cat owners can go about enjoying their boats….everybody’s happy!