Mobile-Content-Service sometimes requests content from RESTBase using non-normalized titles, primarily using spaces instead of underscores. This makes it hit 301 redirects increasing latency. It's not a huge deal for MCS, but still would be nice to fix. Primarily the bug is present for File pages.
|mediawiki/services/mobileapps : master||Use db titles when requesting page content from Parsoid|
Title normalization converts page titles to their canonical form. This means capitalizing the first character, replacing underscores with spaces, ...
(OTOH https://www.npmjs.com/package/mediawiki-title seems to use it like you do. But I think the mediawiki.org definition came earlier.)