Currently the search addon limits itself to 1000 highlights by default. Contrast this to monaco's 20000 results before it gives up highlighting. When we increase our limit to 20000 the search itself ends up blocking the renderer pretty significantly.

Here is a profile using my i7-12700KF 3.61 GHz:

test file test.txt

Note that the search is also not incremental, so all successive searches take the same amount of time even for non-regex searches. #5177

VS Code issue: microsoft/vscode#230365