7H isn't the problem, the game driver is. That's to be expected with the bundled driver because it doesn't flush the cache properly. The cache is a very sore point. When getting the cache to work properly in test builds with honoring cache limits, evicting textures correctly, and correct order of operations, new issues like battle texture corruption have shown up. It's the horrible gift that keeps on giving. The only reason to keep trying to solve it was to keep best performance, but that is no longer necessary.
FFNx is an updated driver that completely eliminated the cache due to all of the issues it was causing but performance became terrible as a result. You had to do workarounds with file formats (that have its own pros and cons). However, in the last days a pretty big breakthrough happened and from what I hear performance is now a lot closer to the older driver even without the cache and without having to mess with your mods. I haven't tested current versions yet, but I believe that was my last and biggest reservation to fully recommending it. Good performance and all of the fixes, stability improvements, and feature updates make it a fantastic and better option. It's a bit hacky to get it to work with 7th Heaven since it is not bundled with it yet, but there are instructions out there on how to install it/replace the existing driver.
Hats off, kudos, and thanks to TrueOdin for all of the time and hard work he's put into the new driver, issues he's had to overcome, criticism he's had to deal with (including from me), etc. all for free and using his time all while keeping it open-source and available for whatever your preferred "framework" or "platform" is. It is much appreciated and makes the game better for everyone. He's a great addition to this community.
