Sorry for necro, but I'm 80% confident that it will be necessary for users to synch with the mod. I say this because of my own experience with a different and unrelated mod creating problems. In that previous ordeal, I learned that multiplayer performs lockstep procedures during multiplayer. Literally, instead of each end user "transmitting" updates of the results of that player's in game actions, the game performs those player actions "on all other players' behalf" according to the game-engine rules in effect at the time of change. (I.e., the depletion of that player's inventory contents when they slap down an assembler and some inserters.)
My somewhat confident guess is that whenever your admin were to "do" anything through the power of Creative Mod, the game clients for the regular users need to be able to recognize that act as "legal" according to the rules. And since placing unlimited items for free, and using the terraforming wand to manipulate and create and destroy ore patches, water, land, etc., those other game clients would need to understand that Creative Mod changes the rules, in the form of literally just saying "rules are not applying to this player does right now."
Hope it helps, despite how long this has gone unanswered.
