Hi again,

On 27.07.2021 02:04, Dmitry Gutov wrote:
> On 26.07.2021 19:56, Ergus via Bug reports for GNU Emacs, the Swiss army 
> knife of text editors wrote:
>> Any progress/suggestion on this?
> 
> Only internally.
> 
> Let me get back to you on this in a couple of days.

Sorry for the long wait, this feature ties into another old discussion, 
and I wasn't sure how to proceed best.

Anyway, here's a patch to try (attached). It should recover performance 
lost back in 4ca13d98c9e while retaining flexibility (and even adding more).

There are still less than optimal places there (e.g. file-in-directory-p 
is not very fast), and the modules list is read from the disk every 
time, so some further optimization should be possible.

But first please try this version.