Following this discussion: Uibuilder and URL case sensitivity - General - Node-RED Forum (nodered.org), @annuello spotted that Node-RED does not follow the W3C guidelines on the use of case sensitivity in URL's.
This is because the default in ExpressJS also does not use case sensitivity.
Really, this isn't quite in alignment with the standards which say that it SHOULD (not MUST).
More critically, the Socket.IO library IS case sensitive and as can be seen from the thread, this can cause at least confusion.
So this is an initial request to see if the default could be changed. However, I recognise that this could only happen in a Major version change as it would be potentially breaking.
Many thanks, J.