I feel your anguish. Or rather, I used to.

Basic rule of thumb has always been to "stay at least one version back from Bleeding Edge". You'll pay much less for what was "Bleeding Edge" last year, but with the updates.

When I was prepping for retirement, one of my first priorities was to allow for a system that wasn't skimping. I knew the beloved Windows 7 OS was soon to be phased out too.

3D graphics has always been hardware needy but the curve has definitely flattened. I'd been researching graphics systems for some years and kept coming back to one company and went with them. That was in 2019 and haven't regretted the decision a moment. Point is, buy quality as it will more that make up the $$$ in time saved in so many ways. Much less frustration being one of those.

Sorry to break it to you, but just jumping to & learning new software, you'll be running into pretty much the same issues if your systems not up to snuff.

That being said, I've found 4.23 quite stable. I always keep the previous version on my laptop though until a version has "proven" itself stable. As others state, make sure everything is up to date where you can stay away from Beta versions.

And I only use the Basic version. Pthhhhpt on their "Premium".  And I ONLY buy something if it hits 50% or more off in the wishlist. Doesn't cost me to wait. No clock 'a ticking. I also export all assets out of DS, but Daz is the starting point. They've literally the best artists on the planet. POS company, but ya can't have everything.

I've a few Gen9 characters, but avoid them mostly. Too much work to recombine things that have always been together.

Probably your G9 memory hog issue is using any dForce hair. Try swapping out to more conventional hair & see if that helps.

Gen9 wardrobe is another story though with the newer Autofit scripts available, and work well with Gen3 through Gen8.1 characters.