When I change a barline (double, half, etc…), Dorico also writes a hidden time signature.
However, in the parts, the multirest is interrupted when the barline changes.
If I delete the hidden time Dorico automatically changes the barline I changed and I get again a normal barline.
For example, in a trumpet part I have:
multirest from bar 1 to bar 4, “my” doublebarline, multirest from bar 5 to…
If I delete de hidden time Dorico automatically changes the barline I changed and I get again a normal barline.
In Dorico, a change of time signatures is always ‘carried by’ a barline, and explicit barlines (that you add yourself) are always potentially representing a change in time signature. If the TS is the same as the previous one, it will mostly be hidden, but it’s there anyway, in the form of a signpost. If you remove the signpost, you also remove the barline.
And special barlines will always break a multi-rest, which is very good practice. A conductor might say in rehearsal to start at some double barline. If some players don’t have it, misunderstandings, wasted rehearsal time, and loss of confidence in the composer/arranger will ensue.