My pleasure on the updates, Shardz -- I like to keep people up to date with what's going on, it's honestly less stressful for me that way because then people know where I'm coming from.
For the installation of 4.0, probably that will be a full install, yeah, although most likely I'll also have a version that works with the in-game updater in some fashion so that people who don't check our site aren't wondering why there is never another official update again or whatever, heh. I did something similar when we switched updaters in order to make that work, that's something I'll be looking at more in July so that no-one gets unintentionally left behind.
The expansion handling will be same as it is now, I put a ton of work into the expansion handling with the first one, specifically so that we could keep adding more expansions down the line without having to reinvent the process. As of the next prerelease, the CON expansion stubs are actually now in place, so that we can start internally doing the early stuff for the expansion. But, the expansion mechanism is really flexible, so you can have CON without TZR, or neither and still get the free DLC, and all those sorts of permutations. Really a ton of work went into making those easy back when I did TZR.