The I was getting at is yes you should do something to support the machine but most don't. Not saying it's a good idea for precision work but it's not like the lathe is going to fall through the floor either.
It all comes down to you use and your intended results of your parts. Want good part? Do your best to eliminate outside influences on the machine tool.
LAst shop I worked in the jib borer and jig grinder where in a separate room on huge foundations with climate control to keep everything stabilized.
My machines in the garage go through some wild temp swings in the winter but not to bad. at most it's a 30 degree swing.
