I wouldn’t be looking at anything that only had a straight steerer, given that virtually all forks now have tapered steerers.
I’d agree with this and it doesn’t make it any easier to source frames…
Probably the only reason to not get a tapered frame is that there are some really cheap used, straight steerer forks knocking about, so if you can pick up a good set (or know how to return them to decent condition) then you might build a bargain. I sold my last pair of SS forks (Pace RC41 carbon) for < £100 on retrobike, but in truth they were still excellent forks providing you don’t mind servicing them every 3 months 🙂
There’s loads of other brands out there too, some of which you wouldn’t even consider. I built my son’s new bike around a small, carbon Haibike (non-electric!) frame, which I didn’t even know existed and it’s made a superbly light, versatile bike for him.