Screencast: Dynamic framerate is problematic
Some apps and online services can't handle dynamic framerates, e.g. Mastodon gives you this error when trying to upload a screencast:
![image](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
Since sharing online is one of the most important use cases for screencasts we should probably aim for maximum compatibility :)
cc @YaLTeR @verdre