While playing around with OS 3.1.4 and WinUAE I noticed the following:
When the 68040.library from the mmulibs package is installed in libs: the OS 3.1.4 SetPatch command consumes some MBytes of memory. In my example about 5 MBytes of fast memory which were missing after SetPatch run. It seems not to be important if there really is a 68040 CPU activated or if only a 68030 is set up in WinUAE.
With 68040.library installed, SetPatch (without QUIET) reports that it is activating some 68040 related patches. Without 68040.library it does not mention 68040 related patches and the 5 MBytes are not missing.