Search Functionality Vs Code
Modifying search functionality VS Code
The search explorer is whack for finding out the last opened element, works sort of for last modified but you're better off using the command palette to searching the last opened files.
You can use a GREP style search but it just shows occurrences unless you really manipulate it.
"VS Code search by last modified"
The settings panel doesn't really work and the File Size extension doesn't work great either.