making a stick property where 2 forge items stay together and are moved together is probably very hard to do code wise. here are some simpler ideas.
1: the ability to mirror any given forge item, for example, the circular staircases in reach only go in one direction, clockwise or counter clockwise, this posed a limited use for them, a simple mirroring ability would be able to make the spiral go both ways.
2: cylinders, not a whole lot of explanation here, couldnt make my columns for a greek temple or whatever in reach, tall, short, flat etc.
3: Trees and plants, put some green under "natural", not just rocks (keep the rocks too). some variety, like one tall tree, a stump, tree w. and w.o leaves, etc.