First please note: when I tried initially to post this comment, and clicked the Gravatar link in the 'Display a Gravatar image next to my comments', instead of opening in a new window, my entire post was erased and so this is me typing it over from scratch. I recommend that contents of this page be saved if branched away from, or better, that clicking the Gravatar link open a new Tab or Window.

Now to my question:
I want to halve both the note values and time signatures in a piece I am currently orchestrating that is written in 2/2, 3/2, 4/2, 5/2 metres, such that the entire score shrinks to be in 2/4, 3/4, 4/4, 5/4 respectively but sounds exactly the same. For example, let's say there was a score in 4/4 time and there was a bar filled with 8 quavers, that this could be shrunk to be a bar in 4/8 time filled with 8 semiquavers.

I have attempted steps outlined in this video, and from a posts in Steinberg forum 'How to halve the time signature?' https://forums.steinberg.net/t/how-to-halve-the-time-signature/127610/8 but only the notes halve, not the time signature. Moreover, a triplet of quavers instead of halving to become a triple of semiquavers as one would logically expect, became the following:
dotted semiquaver, then two demisemiquavers tied together, then a semiquaver, then a demisemiquaver tied to a dotted semiquaver, then another demisemiquaver tied to a dotted semiquaver, and the 'triplet' was over a beaming that exceeded the expected three pitches and trespassed on notes after it.

This is possible in Sibelius using Halve Note Values, which exactly halves all note values including tuplets, the time signatures, and shrinks the entire score to half its value, such that it plays back exactly the same. How can I achieve this in Dorico?