I legitimately have to try this now.. I'm hearing a lot of positive results. (And keeping in mind this is the BOOT up speed.)
I wonder if the boot up speeds back up after doing this is because when it's enabled/shows at startup, it caches everything at the very start rather than possibly while at a loading screen loading into a lot possibly? (In which case, having the show at startup disabled means that when you load into a save game, it caches all of your CC/Mods THEN for use instead of at the very start.)
Although, I really figure I might be wrong.
Also, since I'm here, for anyone interested in it, the Multiplayer Mod (SimSync) supports more than 2 players now, and you can have as many as you want, but the more you add clients, the more the host will need a beefier PC – it’s a lot more networking / logic for them to handle.
Mentioning that for anyone interested like me.