Why doesn’t Infuse use a global database (SQLite for example) which is stored on the server? Would certainly be much more efficient than every user always has to go through a scan to get the same results that another user had already received.
You could create a global database on the server, where all informations about all files/movies/series are stored. Then you can also manage which users have access to which shares/libraries.
The eternal scanning is annoying, especially when the pages that are used for metadata take a long time to respond. Also, an initial scan of a large library takes an extremely long time when a new device or a new user uses Infuse and he must then manually correct all incorrectly recognized movies and series again.
The whole data processing of Infuse is not efficient, not up to date and also not well thought out. There is really extreme potential for improvement, since years.