Tony, I think you have a great space for your model work. Something comfy and easy to clean and your tool selection fits the needs perfectly!

Since your association has a limit on shed dimensions, how about multiple sheds? Or maybe you could plunk down a few co-joined shipping containers.
There may be an exception if things are on wheels (like a travel trailer). Then you could go really big with only the addition of a set of wagon wheels screwed to the sides.