I would very much like to use mills in SE for Poles, as well as using Folwarks for any other civ, both as eye candy.
Not asking for any new civ specific sprites for the folwark; I just like using all the assets. The folwark is a pretty building, and I would like to use it without having make extra Pole players and then go through scripting to get them into non-Pole towns.
Thanks!
Cant you just make gaia poland and put the new mills?
Haven’t used the scenario editor with DotD yet, but I’m sure I saw a Folwark in an enemy base in the last scenario of the Lithuanian campaign and none of the players were Poles
Why can’t they just made the mills 3x3 
Editor units are not behind a paywall
A nice addition I notice FE
That might work; I’ll have to see. Still, I have never understood some of the unit restrictions. As for instance, why earlier age units disappear when you set a player to a later age (EG, Imperial age cannot have man-at-arms). I know that this seems situational, but it has been a restriction I had to work around before. I think it would be nice if every unit (and building) was always available in the editor, just for creative reasons.
I know I am resurrecting this but I just noticed another interesting SE-Folwark related issue.
Might be aware. If you place a mill in the SE, then play a Poles, or switch the civ to Poles in the SE, the mill will (obviously) switch to a Folwark - but the game thinks it’s 4x4 tiles and places the 3x3 Folwark in the middle, leaving about a half tile of space between the building and farms. You still get the farm bonus, but it results in a really ugly layout. Only newly placed Folwarks will display properly and get the nice 3x3 grid of farms.
The work around is the following trigger:
C1: Research Tech: Poles
&
C2: Objects in area: 1 alive mill
E1: Remove Object (mill) from area
E2: Place mill at the exact same spot (Folwark placement tile is the center tile where the Mill’s placement tile is the right most tile since it’s 2x2)