Tool for embedding electrical boxes in the wall

A construction tool for electricians, for embedding electrical boxes in the masonry (wall) before plastering.When pre-embedding electrical boxes in a constructed wall (brick, masonry, etc.) (using plaster, other adhesive, or filler), there's a problem because the front of the box should protrude slightly from the wall, so that after plastering the entire wall, it's flush. However, it's difficult to embed multiple boxes (in a multiple configuration) so that they are perfectly spaced apart (the standard is 71mm between the box centers), each box is straight (not tilted up or down), and that they align horizontally (or vertically). You adjust one, and the rest get skewed. Almost all of them are correct … but the plaster has hardened and can no longer be adjusted...ARGH!!! Horror! Additionally, even if everything went straight, you'll discover during plastering that the boxes are sticking out of the wall (you have to mill the front, and plasterers are furious), or the boxes