I went through round of optimizations for timelines recording, playback, and file writing and loading, to allow for very large numbers of messages.
TWO has now been tested with projects that contain over a million messages in a recording.
And even with clips that large it was quite responsive, when with earlier versions, it would slow down with about a fifth of that.
With one caveat that still needs resolving: if a clip contains that many messages, TWO will still grind to a halt if you try to edit the clip’s content. That will be fixed in a future update.
So if you experienced bad performance with previous builds, trying to record large clips, download this new 0.9.25 version, which is bound to be far snappier.