WOMOIWIW: What Org-mode Opens is What I Want
That's a cool feature I've to say.  And the code looks excellent, I
suppose you could argue for one or the other wrt. cond vs. if
etc. but that's pointless pedantry IMO.
Given that it works flawlessly (tried locally and via tramp as well), I
was unsure there was actually anything to say here, but I found two
points that might be of interest:
Firstly, while the :around combinator works fine, it might be more
appropriate to use :filter-args, since it's really just filtering the
arguments:
(defun my-org-link-open-advice (args)
  &quot;Advice for ORIG-FUN that expands patterns in 'file:' LINKs.
See `my-org-expand-file-link' for more information.
Optional argument ARGS are passed as-is.&quot;
  (list* (my-org-expand-file-link (first args)) (rest args)))

(advice-add 'org-link-open :filter-args #'my-org-link-open-advice)

The functionality is absolutely unchanged of course.
Secondly, and this is conflicting with the previous point, I could
imagine using the prefix argument (so C-u C-c C-o) to
distinguish the two cases of whether to run the original behaviour, or
not, like so:
(defun my-org-link-open-advice (orig-fun link &amp;optional arg &amp;rest args)
  &quot;Advice for ORIG-FUN that expands patterns in 'file:' LINKs.
See `my-org-expand-file-link' for more information.
Optional argument ARGS are passed as-is.&quot;
  (apply orig-fun (if arg link (my-org-expand-file-link link)) arg args))

To quote the function docstring for org-link-open:

ARG is an optional prefix argument.  Some link types may handle it.
For example, it determines what application to run when opening a
&quot;file&quot; link.

This might interfere with the above idea, however practically I couldn't see a
difference with the unadvised function and this argument being present
or not, YMMV.