I think you will find that with a minimum radius of, say, 6ft, the FY entry curve will start at about 7ft from one end which means that an L-shape is much less efficient than you think as you then have only a 9ft straight portion with, potentially, lots of curved pointwork. The end of the FY entry curve would only allow about a 4ft-long traverser/sector plate or w.h.y.
You can still do a lot with a straight 5m/16ft run without having to compromise by using tight radius curves or A5 turnouts on main lines. Less is more!
Dave