It’s probably off topic in Shift sensitivity: I run recently in a time out with intitle in Commons. I searched for SVG files with file extension in upper case letters and even narrowing down to SVG files with filemime wasn’t enough (over 1.7 mio files). Luckily I did not need all of them, just some examples for pointing to a script bug related to these upper case files. I probably thought of the timeout danger only because of that incident.
Topic on User talk:TJones (WMF)/Flow
That makes sense. There's always context and exceptions and exceptions to the exceptions. Commons has many more files than even the biggest Wikipedias, and the ratio of body text to title is much lower. And of course what you are searching for matters, too—I changed my example from dog (which doesn't time out) to mark (which does) because I can see wanting to distinguish mark/Mark. It's hard to give specific advice to an IP address user with so little context!