[SOLVED] Multiple Time Signatures for a whole piece

A piano piece by Bach has two time signatures: 4/4 + 12/8. When entering the notes in 4/4 the triplet signs can be hidden, so that looks correct. But how do I get the two time signatures in the first bar? I guess I have to fake the additional 12/8 somehow, as I did in another notation program (see attachment). What’s the best way to accomplish this?

Create an interchangeable time signature. Type 4/4 - 12/8 in the M popover. Note, there must be spaces around the -.

Then in the properties panel, tick “Common/Cut common” to change the 4/4 into C, and set the separator to ’ ’ (i.e. nothing).

I wasn’t expecting it to be so easy and elegant. Thank you, Rob.