This is a pretty important bit of kickstarter info and what you guys are communicating that is still not quite clear to me.
I assume the stretchgoal is for tools/sdk/steam workshop integration/support on official servers.
If that is the case and you are not locking down the game by hardcoding everything and you still do provide privately hosted servers at the minimum goal then modding is still entirely possible, community just needs to build the tools.
If what I said above is true then you should clarify that stretchgoal to people as you might be communicating that without that goal you can’t mod the game which is not true. Starcraft Broodwar had no SDK and blizzard still calls maps mods yet total conversions and other real mods are abundant for the game and are all built using community made editors and tools.
I just really felt this needs to be clarified quickly!