There may be editor mods and I also may be blind but...

The smallest available Gridsize you have in the Editor is 100m, which is not ideal for placement and correcting placement. What about smaller grids you can turn on and off? Also what about a implemented Ruler function on which you can slide your placement?

Currently there may be more pressing problems with 1.22 but this would be a nice easy boost to quality of life for editing

hint: you can use grouped units if you need a straight line and set distances by copying 2 set lines