I want the Camtasia video recording part (selection) accelerated? Do you have any tips on how to do this?
Cut off the part you want to speed up, right-click on it and select the "clip speed" option in the menu. Enter 200, 300 or even 1000% if you want to speed up, or 10, 20, 30% if you want to slow down your video.
If you want to slow down the speed of editing clips, you need to make a new track and move the selected part to it. After that you need to edit the clip speed and it will work fine.
https://gyazo.com/e43c408ed3be39e30a07b98f1081e156
Please note that disconnecting it from the rest will not work.
https://gyazo.com/d076b39161739dcaeb2a48899a985734