Is it possible to start the mod in an existing savegame?

Sure, you can turn it on and off at will. However, the mod really only does stuff when a new player is created, so adding it to an existing game won't give current players any equipment, but you could join with a new name to generate a set of equipment.

is there an command to spawn into an already made save ? i would like to use this mod, but when the game is already started, the armor won't spawn when activated mod.

One could join with a new name, or have another player join. Currently there is no way to trigger this for an existing player in an existing save. I will look into a way to allow this, whether on demand, or possibly on death.

I tried joining after changing my name on here, as well as signing out of my account. No luck :(

Update: hosting the game as a local multiplayer, getting your bots and putting a chest, save, then load in regular singleplayer and they're there. Cheers!

I am releasing version 0.4.0, which now also outfits respawning players. To add this to a save game, now all you need to do is respawn to receive an equipment loadout.

I've got a game going with enemies disabled. Can I assume that builder bots are impossible for me?

Get yourself run over by a train, or add the mod respawn button.