A major missing feature is the ability to search scrollback, i.e. cmd+f on Mac, ctrl+F on Linux. This issue can be implemented in multiple steps, not just one giant PR:

• Core search functionality in src/terminal (Naive search internals (core only) #2885)
• Make core search work simultaneously to PageList read/write to allow multi-threading
• Implement multi-threaded search, including data modeling for notifications of matches
• Search UI, glue in apprt

We can also support search only in certain modes as long as the apprt glue is all there for someone to come along and finish it up. For example, only macOS, Linux+GTK, etc.