Yep, definitely the simplest way would be that hull weight change, but I wonder what would happen to the people who have ventured out into the black in their annies and would lose their jump range and get stranded in the worst case
To be a bit more serious, I've already suggested a reasonable solution.
Let's take a look at "the big three", in standard trim, to see how things stack up with light alloy hulls.
Anaconda: Hull 400t / Integrity 945
Corvette: Hull 900t / Integrity 666
Cutter: Hull 1100t / Integrity 720
The Corvette and the Cutter have integrity of
roughly 0.7 per tonne.
The Annie, OTOH, has integrity of around 2.4 per tonne.
The Annie's hull is 3x tougher than anything the Federation or Empire can produce.
More reasonably, the Annie's integrity
should be around 270 - with a light alloy hull.
That's the first change FDev should make.
Simply reduce the Annie's integrity to around 270.
That's probably not going to affect anybody who's out exploring because it won't change the weight of their ship (given that an exploration ship is likely to be fitted with a light-alloy hull) and the integrity nerf won't matter, anyway, 'cos their hulls are probably already
at 0% integrity after any time exploring.
Now let's look at upgraded hulls.
Anaconda: MGC Hull 460t / Integrity 1838
Corvette: MGC Hull 960 / Integrity 1295
Cutter: MGC Hull 1160 / Integrity 1400
The Corvette & Cutter
now have integrity of around 1.25 per tonne.
The Annie now has integrity of 3.99 per tonne.
The second change FDev should make is to increase the weight of the upgraded hulls for the Annie to make the overall hull-weight similar to it's competitors.
Make the Reinforced alloy hull weigh around, say, 250t and increase the ship's integrity to roughly 900 and make the MGC hull weigh around 400t and increase the integrity to, say, 1200.
It'll never happen, of course, but maybe it's worth pointing out that there ARE ways to fix it.