token for specific instrument name in a doubling situation?

I am working on a piece for quartet involving multiple doublings. In particular, I have a player with four instrument doublings called for witin the piece. When creating parts, the token used “@layoutname@” listing all four instruments. In the multiple movements of the piece (each written in a separate flow) I only use one or two instruments. My question: Is there a token I could use to describe the currently used instruments at the upper left corner of the “first” master page? On a closely related question: sometimes, if there is a delayed entrance, Dorico will only write the instrument name after the rest, as if an instrument change has just taken place. Is there a way to indicate to Dorico the instrument is used fro the beginning?
Many thanks!
I Especially appreciate the recent version improvements: yay metric modulation tempo markings!
(edited for clarification)

Regarding the list of players used: I don’t believe so. The only related tokens I know of are {@playernames@} and {@playerlist@}, but they list all players in the project.

I could see that being a helpful token, actually. Something like {@flowNplayernames@} or {@flowNplayerlist@}, where N is the flow number, and the token lists the players present in that flow.

Thanks, Dan. Yeah, that would be great.

{@flowPlayernames@}, can we have it, please?

A work round would be to have two players in the score - for example a clarinet which sometimes doubles sax, and a sax which sometimes doubles clarinet.

Then, in each flow you include the player with the correct starting instrument and omit the other one. That way, the instrument name on the first system of the flow will be correct.

The part layout for the performer will contain both players.

Another answer to this question (I think!) is yes: ensure you set this Layout Option within all doubling/tripling/quadrupling layouts: