Closing this for now, if you still need help please follow the instructions provided above.
Hello Kristi, sorry for the delay. I am not detecting any lag introduced by the script, it is possible that you might have installed another extension or script that is causing conflicts with YT+. Please follow the troubleshooting guide to see if you can find out what is causing your problem: https://github.com/ParticleCore/Particle/wiki/Report-a-problem#troubleshooting
Currently the preview box in the script info maker works correctly with base64 images, such as this one
<img src="data:image/gif;base64,R0lGODlhDwAPAKECAAAAzMzM///// wAAACwAAAAADwAPAAACIISPeQHsrZ5ModrLlN48CXF8m2iQ3YmmKqVlRtW4ML wWACH+H09wdGltaXplZCBieSBVbGVhZCBTbWFydFNhdmVyIQAAOw=="/>
However, when the user submits the script description containing base64 images the website looses the source, returning simply an empty
This image method is not appropriate for big images, but for small images it works really well and prevents the need for users to host their own images somehwere where the connection might not be
https (causing the browser to show an insecure connection warning when visiting OpenUserJS; this one is a perfect example of that Anti-Adblock Killer | Reek) or risking the image to die, or its link to change for some reason.
YT+ will not support the new design. A new extension is being created from scratch just for the new design.