Attempting to run libreoffice with W^X enabled results in this failure to start:
# sysctl kern.elf64.allow_wx=0
LibreOffice 7.0 - Fatal Error: The application cannot be started.
Extension Manager: exception in synchronize
elfctl(1) can be used to tag binaries that require W+X mappings; discussion about a canonical method of applying these tags is being discussed in PR252629