Build tiny 1x1 floors or use the 1x2 beams to make a level line to attach the 1x1s to.
I have been able to squeeze the bellows just directly over the forge for example and all upgrades but the anvil smashed up against it and under it. Just have to be extremely patient and find the right pixel to aim at.

Once I get a comfortable position I remove the beams and floors and the upgrades stay there because they are usually touching a wall at that point which offers them support.