I was thinking it changed years ago, but you’re probably right. Too many years have elapsed. 
But which editor? Open Key, Open Drum? To close, assuming it’s focused, I use Windows ctr+w. There must be the equivalent on Mac?
Work-around:
Since you use Metagrid, this should be easy because you have the advantage of longer macros with delays which Cubase does not have.
Yeah, sorry…the .gif is quite rough to completely see what’s going on.
In that .gif, I have 2 displays. One on top of the other. The bottom one is a wide screen.
Look at the bottom display. Starting out, on the left side of the bottom display is the Arrange Page with a Toontrack vst track in focus. On the right side of the bottom display is just Windows wall paper. (I tired to eliminate as much non-relevant stuff for this example)
On the top display you see Cubase Supervision in the upper right. Below are VU meters. On the upper left side of the top display is the History page. I make lots of mistakes so it typically stays open.
Now, press 1 button in Metagrid.
The Drum Editor moves to the lower display in full screen. The Arrange Page has moved to the upper screen, and the history page has closed.
I do whatever editing I want, then with a Metagrid default Workspace button, go back to “normal” mode.
The following Metagrid macro is probably worthless to you because every persons configuration is different. I’m using 4 displays, and 2 of them in link mode. However I’m confident you could take these ideas and achieve what you desire.
With the track and part in focus:
bring to front
.5 delay
open drum editor
controller lane set up #1
.3 delay
workspace 8
.4 delay
open drum editor
.3 delay
history
.3 delay
ctr+w (windows close)
ctr+sft+M (windows maximize)
zoom to locators
.5 delay
macro 224 (zoom out many times)
This works for me. And for the smart people to hopefully chime in, I’m always willing to eliminate steps or do anything that makes the macro smaller as long as the result is the same. I’m here to learn.
I have different macros that open editors that are dependent on my cursor, locators, and one that opens range duration.
Also, fwiw, I am just using Metagrid Legacy. I’m scared of Metagrid Pro however I have found a person who is willing to help me make the transfer in 2026.
Merry Christmas!