I have some idea of the plastic molding business since I worked in such a facility for some time. I am aware of various materials such as PVC and CPVC--it seems Collect-Aire Models was using PVC, near as I can tell--versus the other materials we see in our ship kits (several older Japanese kits of the Yamatos are ABS !); I understand the concept of thermal expansion and contraction; the concepts and methods of cooling molds by way of mold design, and; the nature of tolerances in general as well as tolerance stackups between components. Therefore, I think the concept of plastic injection molding is fairly well established here, as has been discussed before, as I allowed and as you mentioned yourself. As I recall, the issue of mold shrinkage was how Monogram cornered Revell when the latter 'pirated' Monogram's B-17G into Revell's B-17F.*
Once again, my comment regards the input...that is, the research prior to any work which ultimately results in the cutting of production molds for the final product. Ironically, your complaint about the tanker shape of the Hornet hull is precisely what I was discussing: someone got the profiles--that is, ultimately, the dimensioning--all screwed up. As I wrote, it's not rocket science to call up the proper profiling and dimensioning; we have that data. I simply wish it was done. Maybe it was budgeting for those particular molds (both Trumpeter's Hornet and Aoshima's Wasp) or perhaps there was simply a royal screwup between two people laying out the research and the cutting of the molds. Early western renditions of Yamato--notably Aurora's--are famous examples of poor research.** But this needn't have happened. As you no doubt know, Aoshima's 'Retake' versions are corrections to their previous new release kits which generally involves correcting the foredeck, the hulls and/or various levels of bridgework on their battleships.
Now, in the final analysis, Aoshima will not likely correct their Wasp--too much already invested--nor should they. Trumpeter's Hornet is another issue entirely; I wouldn't bother with it. My comments address the modelmakers who know the dimensions they need to arrive at and acknowledge that they know how to get there. But if they don't get the dimensioning right to start with there is no mold in the world which will correct for that. The horse is dead; we can stop flogging it. Hopefully, they'll do a bit better next time; they're doing very well as it stands today. Again, I'm not complaining, just observing. Thanks for the insight.
* -- http://paulbudzik.com/tools-techniques/B-17%20Conversion/monogram_b-17_conversion.html
Note: (Control+F...insert Revell...you'll get 5 hit
** -- http://www.steelnavy.com/AuroraYamato.htm