With v256 we did something about this: there's now a new D-Bus call and systemctl command, which we just called "sleep". It's supposed to abstract this mess away, and just get the job done, according to what is available, and based on system-level configuration in /etc/systemd/sleep.conf if needed.
This relieves tools and desktops to bother what precisely to when suspending, and just make the system "sleep" and let the lower layers of the stack then figure…