What is the current situation with this? Can it be done?
Historical threads show a high demand for this. I have a string quartet score where at certain points it is just simply wrong, when an instrument goes into a solo and a long tacet for the others, they don’t need the cautionary time signature, and it is actually misleading - because in this modernist complexist piece the time signature changes every two or three bars and does not stay at the initial cautionary one for very long at all, and so counting in that time is wrong. All the other use cases on this forum seem perfectly valid to me also.
Waxing philosophical as a new user come from ten years of deep Lilypond professional work , I admire the way the Dorico prevents one from making musical errors in most cases - I understand this is helpful to people - but for experienced engravers who are working outside Common Era period and so on, I am very happy to be given enough rope to hang myself - decisions I make about engraving practice should not be barred by a tool working to stop me. Word processors do not stop me from using my own grammatical constructions if I want.
I think having to be forced into a workaround with flows and so on to simply hide a cautionary indicator is contrary to the fluid way Dorico does almost everything else.