Hello Alexis,
I'm happy to report that this was added about a month ago!  Builds from mid-Oct and later should have the "id" option to the "open" command, see

<https://www.rbvi.ucsf.edu/trac/ChimeraX/wiki/ChangeLog>
<https://www.rbvi.ucsf.edu/chimerax/docs/user/commands/open.html#id>

Best,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Nov 16, 2023, at 4:38 PM, Alexis Rohou via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
>
> Hello,
> Not sure whether this already made it in to the backlog, but I'd vote for this as a useful feature, especially when scripting.
> Cheers,
> Alexis