My personal take on ULF is after a certain format size, the choice of format is dictated by the size that one would desire to contact print, but for enlargements, a smaller LF format one has (or access) to the proper enlarger to use... (The old reason for ULF was before enlargers and electricity, cameras were chosen for the max size they could contact print, as enlarging was super hi-tech + $$$, so to offer that size to their clients, you needed the big camera for it...)

Even 8X10 was usually retouched for portraits (easy on the big neg), and contact printed, but enlarging shrunk the camera needs (when enlargers became cheap and available), but I agree finding an Elwood is a start, but for very large blow-ups, the greater precision of the better enlargers is more needed, as little enlarger alignment issues will blow up more the bigger print you get, where you get a nice print (except for that soft edge etc)

Hope you find a nice one!!!!

Steve K