It would probably work
That is, it would certainly work with one issue I can think of: A loose footed main is actually extended down beyond the top of the boom. This is to minimize leakage of air at the bottom of the sail, and the associated reduction in efficiency. But the efficiency loss is probably slight, so it is your choice.A properly cut main with a bolt rope on the bottom should have a "shelf" in it. This allows the bottom of the sail to belly out if you loosen the clew outhaul - the same as a loose-footed main. You might give it a try, although the clew outhaul may need some encouraging if you slack the line.Finally, good sail shape is very a much a function of sail age - it was hard to get any good shape with the 23 year old main on Lady Lillie when we bought her.DavidLady Lillie