Change 338305 had a related patch set uploaded (by JGirault):
Open the sidebar "More details" by default at high resolutions

https://gerrit.wikimedia.org/r/338305

Proposed behavior (suggested by @Yurik, thanks!) is as follow:

• [NEW] Anytime the map is rendered full screen, a vertical offset is applied to the map center to take the dialog footer into account.

Now depending on the sidebar display status:

• [NEW] When the dialog opens, if screen > 1024px , the sidebar is now displayed by default, and the map is centered accordingly (with an offset to the initial center to push the center to the left)
• When the dialog opens, if screen <= 1024px , the sidebar is still hidden, and the map is centered to the screen (without the horizontal offset).
• [NEW] When the dialog is already opened (change route via URL), if screen > 1024px AND the sidebar is visible, the map is centered accordingly (with an offset to the initial center to push the center to the left).
• When the dialog is already opened (change route via URL), AND the sidebar is hidden, the map is centered to the screen (without the horizontal offset) regardless of screen size.

Not sure this is clear enough, but at least I tried :)

@JGirault, looks awesome, thanks!

Change 338305 merged by jenkins-bot:
Open the sidebar "More details" by default at high resolutions

https://gerrit.wikimedia.org/r/338305

Note. This was reverted a year later in T187919.