I'm on v72 now and the Dev tools console feels even slower. It now freezes with just a few thousand log messages.
I also have to keep clicking the clear button to prevent the page from freezing if the dev tools console is open when loading the page.
Maybe make a perf switch in the console, which dumps the text without formatting or other features. Something that can handle one million lines of logs and search in it. Being able to search the logs is critical. Filtering doesn't work as I need to see the surrounding logs, what happened after. I don't need to see all one million lines at the same time though, it can be buffered to only show 100 lines above it and 100 lines below it. Chromium has such an optimization. But search is a bit slow.