When trying to reply to a message in a large folder (~ 110.000 messages), the editor is loading correctly - but using it becomes unbearably slow. Entering of text is possible, however it will take a few seconds for text to actually be displayed.

I cannot quite put my finger on the root cause of the issue. My best guess is that it has something to do with either the allocated memory on the client or the amount of DOM elements on the page.

The latter is a complaint of the Chrome Audit Tool - the former the result when taking memory snapshots in Chrome's Dev Console: A snapshot in the 110.000 mail folder yields an ~ 50MB snapshot. Doing a search in the same folder beforehand (and thus limiting the amount of displayed messages to ~ 40) and then taking a memory snapshot, the result is only about 25MB.

When cross-checking on Firefox, the issue is still persisting there, however less pronounced than on Chrome.