Fun Expander is the tool you want, it can limit speed, Great tool.
You can also use it to speed up existing funscripts or increase or limit stroke length too.
New Version (2.5.2) - 2022-04-11:
- Compatible with ffmpeg V5 (command “-intra” replaced with “-g 0” - Compatible with ffmpeg V5 (command “-intra” replaced with “-g 0”)
Download from Mega Version 2.5.2 Download from Mega Version 2.5.2