OT: full measure duration in compound triple

[charles_piano]

A few months ago, a user was copying a modern piece with irregular Time Signatures where the full-bar notes had to be double-whole notes everywhere:

Double Whole Note

[Screenshot 2025-04-10 at 21.41.53]

And more recently, same with whole notes:

Measure without time signature/open time signature

Hi! I’ve attached an image of a score I have to arrange. How do I recreate this in Dorico? I’m now using an open meter, which allows me to put all the notes of the vocal line in the measure, but then the piano chord also needs to be that lenght, instead of the single chord that is used in the original score. Is there a way I can achieve this? [Scherm­afbeelding 2025-09-10 om 08.14.45]