On 30/07/2023 09:34, Jonathan Fine wrote:
> Hi
> I wonder, does the LaTeX companion contain useful information related to
> this topic?
> Jonathan

I am not sure what it would say: as I've already mentioned, the change 
was essentially technical and not intended to impact on end users. The 
fact that it was predicated on the idea that all file operations use the 
same search approach is one that LaTeX has relied on 'for ever' as it's 
true of \openin and \input, which are the 'classical' file reading