In JOSM 13576 it is possible to select (s- key square) a group of buildings. Both ways and nodes are selected. With “shift +U” The nodes are deselected. Now you can align this group to a few nodes on a highway or from a buildings which is good positioned., Q button aligns all buildings to that way.
In JOSM 13878 (earlier as well?) This option don’t work anymore . With the group selection only the ways are selected from the buildings
You cannot select nodes of a highway or buildings to align the buildings.
So the possibility to align a group of buildings ( from a sloppy mapping) isn’t there anymore ?