Yes, I have a 4K too, but most apps don't scale well to them (like Lightwave.) Terragen 4 works great on my 4K, but some of the panels, like Objects, don't use the space efficiently. You can expand/contract the top part using the double lines below the "Populate All" button, but the expand range is limited for some reason (there's quite a bit of unused "white space" above the "Project Settings" button.
However, TG4 is quite usable on a 4K monitor, and for me, it's more of an irritation than anything else.