I haven't read this entire thread, and I haven't restored a hardtop. So take this with a grain of salt. This may have been discussed before. But my suggestion is know the chemical make up of the materials before researching restoration methods. And the type of paint involved.
This isn't to say any of the methods above are wrong. This is just my experience spending a shit ton of time attempting various restoration projects. Only to find out they didn't work at all. Or didn't last long enough to make them worth the effort. Or that I should jumped to the restoration method that even though was more expensive and time consuming - was the only one that provided long term enough results to make it worthwhile.
So this is just a suggestion:
I have restored the plastic flares and trim plastics multiple times with various products and techniques, wasting a lot of time, energy, and money in the process.
If I had to do it all over again, my first move would be doing deeper research to identify the exact chemical compounds and materials used in the original parts. Jeep plastics aren't standard; they seem built for trail abuse, but don't hold up as well to intense UV exposure. And sometimes don't work at all with many products that work wonders in every other vehicle plastic out there. Products that work wonders on other vehicles often fail much faster on a Jeep. Or just don't take.
Before diving into trial-and-error, a wise move might be figuring out which other industries use those same chemicals and materials—maybe even reaching out to a 3M engineer. Those guys are a huge information source and will talk at length to anybody.
AND THEN check marine, RV, and heavy-truck forums. Or other industries using the exact same materials. (Just like Jeep flares, the hard top and it's paint might be a very different product.) Boaters, camper owners, and professional restorers deal with harsh sun exposure constantly, and they’ve likely already perfected long-term solutions for similar plastic or fiberglass compounds. And know exactly not just what works. But also how long each solution lasts. And whether that's worth the time and effort avoiding a repaint.
My issue with most plastic restoration methods (and again I'm not talking about hard tops. Just restoration projects in general) wasn't that they didn't work initially, but that they didn't last—something you only realize months down the road. In high-sun climates, UV degradation is an ongoing battle (I’ve even rigged a tarp across my carport just to keep the afternoon sun off my trim. Because I know sun damage is probably the biggest maintenance issue facing our Jeeps. And how time consuming it can be. I'll do anything to avoid it in the future!

).
The results posted above look amazing, and a 2-hour buff job is definitely easier than a full repaint.
But based on my past experience with temporary treatments, taking the time up front to research the exact material science—or deciding if a full repaint makes more sense for your climate—can save you a lot of repeated effort and disappointment a year down the line.
To recap:
Do we know what exact chemical compounds were used in the hard top? (For instance - Jeep plastics are a completely different plastic than other vehicles. Forever Black has worked and lasted for years on my GM vehicles. It failed to even take on properly prepped Jeep flares. Not to mention the other numerous flare solutions that are definitely half assed and rarely last.)
Do we know the chemical make up of the paint? Is there a better one?
Have we identified any other industries using these?
Have we researched those industries long term solutions? And done a cost to benefit ratio analysis?
In simpler terms, is it worth it or should I just jump to a repaint? And save myself countless hours, money and time - I could have put into a repaint or longer term solution?
This isn't to say any of the above solutions are wrong. I just think you might be better off starting from zero, figuring out what exactly your dealing with and what other industries you might get help from, and identifying the long term effects of each solution - each ones cost and time versus it's long term results - before you try anything.
What I'm saying is - identify all your choices first. Before choosing one. At least then you're informed. And know how much effort and long term affect your going to have - compared to the other solutions.
I spent months going from one plastic restoration solution to the next. Convinced the latest one was the solution. Had I taken my time and compared all of them? I wish I had just skipped to repaint. Ultimately that was the final solution.