I would like to share my workaround for graphical scores that use a box to mean a gesture that should be repeated ad lib.
It looks weird in Dorico and in the print preview, but it looks ok in PDF and in print.
Create text: Shift X
Paste following text:
Square version: setup:
First character is 115pt in size, and has letter kerning set to -2pt
next set of characters are 8,7pt in size, has letter kerning set to -1,5pt and baseline is shifted 41,95pt
the ending is 11,6pt in size, and is shifted 38px upwards.
box: 76,8pt, 200%wide, kerning -2pt
last char: baseline 28px
Getting rid of multirest hack:
insert a whole note (D’ in treble clef) in every bar
change notehead to diamond old style
change color to white
change voice column x offset to -2 1/8 so it is under the barline and makes a weird notch.