We appear to have had very similar experiences. Some printers we have had using certain resins can print some models flat as long as the models have the right geometry.

We have found that some printers (Phrozen Mighty 8K, made in Taiwan, and Elegoo Saturn 4 Ultra 12K, made in China) can print some of our models flat without too much trouble.

Other printers we have had, especially those that use a laser and/or have fast build platform lift speeds set by the factory, struggle printing models flat, (e.g. Form 2, Form 3 and Form 4).

It has been our experience that the flatter, thinner and longer the model (e.g. masts and nameplates), the more likely the printer will struggle to produce the model without warping it.

We have noticed that many models printed by certain Chinese vendors and sold on eBay such as 1/350 scale aircraft catapults for ships, masts, and other objects with a lattice structure, often arrived badly warped and unusable. Replacements sent by the vendor were just as "banana'd".

Sometimes, dunking a warped catapult model in very hot water for a minute or two helps the model return to its desired shape. But not always.

Resins we have tried include those made by Formlabs, Sunlu, Elegoo, and Siraya Tech. They all have their strengths and weaknesses.

We haven't tried a Creality printer but the specs look good.