I hide whatever isn't in the viewport. Rendering a scene this big only takes about 30 minutes @ 2560x1440, 2800 samples. I'll do about 30 images and let them render overnight and while I'm work. The problem is actually rendering though, it's the work.
5950x, 64gb 3600mhz RAM, RTX 3090, M.2 SDD. Even with all this hardware, it takes a long time to open big files or manipulate high-detail assets in the viewport. Could be because I'm rocking a huge 4k monitor though. If I dropped back to an HD 1920x1080 monitor everything could move faster since the video would be easier to render.
Or something, I don't know how this shit works.
I feel ya!
The most frustrating thing for me about Daz is not the render times (as you say, it's possible to run those as a batch during downtime). It's the clunky-ness of the user interface and the slooooow load times for assets.
I don't think monitor size makes a big difference (unless you're working in Iray preview mode, in which case yeah it would have some speed effect).
If you haven't already done it, there's a setting in Daz config that makes the UI much snappier than the default install - apparently they have it OFF by default (and sometimes it goes back to OFF in a version upgrade) because there is risk of incompatibility with some video drivers meaning the software won't even start up.
Anyway, try changing "Edit -> Preferences -> Interface -> Display optimization" to "Best" and see if it helps.
Second big speedup is reducing the numbder of installed morphs. Apparently having lots of morphs installed is also a big killer in the load time of assets - the app has to go through and pre-load up every single morph slider, just in case the figure needs it.
There's a fantastic free tool by F95 user
NSware (
https://f95zone.to/threads/daz3d-manager-tool-0-6-09-08-2020.33888/) that allows you to uninstall/re-install morph assets from your Daz folder, which can make a big difference on figure and scene load times.