Yes. Some horizontal coils can be installed in either direction depending upon which side the lineset comes in.
I'm a big fan of adding a mini-split to the second floor or to a distant area of a house where the main HVAC system falls short. The mini-split just picks up where the main system leaves-off.
Not many basements in North Carolina, mostly crawlspaces. Horizontal systems get stuffed into wet, buggy crawspaces or in attics (which are ovens in the Summer) around here
California is now requiring static pressure tests for new installations.
I'm not a fan of that, it just seems wrong to run the coil "backwards" even if it's designed to work that way, seems like it's asking for exactly the sort of problem you encountered.
I've thought about putting a mini split in my rec room downstairs, possibly a second one in the guest room to replace the baseboard heater in there but I don't want the outside to get crowded with outdoor units. Cooling is not a problem year round but the downstairs is very difficult to heat in the winter, the heat all just flows upstairs right away. Years ago I put an insert in the fireplace in the rec room and that works great but requires some effort to get it going.
Not many real basements here either, but the classic 70s split level house is the exception. These typically are built in hilly neighborhoods and have a daylight basement where one side of the house is built into the hill. They were commonly sold with the basement unfinished or partially finished as starter homes, the idea being you'd live on the upper floor and then finish the basement to your liking later on once you can afford to. I've never seen a furnace in a crawlspace or attic out here and I hope I never have to deal with one, sounds like a real pain. My mom's place has a crawlspace and I don't enjoy being down there, her furnace is in a closet, the supply plenum is in the crawlspace and the return is in the attic, probably 90% of houses here have it in the garage and the rest are like hers. Regional differences are interesting.
Static pressure test seems prudent anywhere whether it's required or not, it's not like the tools required are particularly exotic or expensive. I only paid around 40 bucks used for my manometer, it was worth it even just for one job and I've found other uses for it. I like having data and I don't mind an excuse to buy tools.