Keep the titles of your Issues and Pull Requests clear and concise. It's also recommended to give a brief summary at the start of the body.
Double-check that someone else hasn't already said or done something that you want to speak about; your post will likely be marked a Duplicate and closed without further consideration. If you fear your issue is similar enough to be confused with another, but different enough to still remain unique, clarify that as soon as you can into your post.
Functional accuracy is paramount. If you want to add an enhancement, think: Was this a feature present in the original Animate script, or otherwise present in a related system? Functionality-altering enhancements are less likely to be merged; you may want to consider keeping them as part of a fork instead.
Security issues should be reported in private, though I have no idea what could possibly be a "security issue" on something like this. Just be careful not to report engine behavior as a security issue; client-sided animations are an intentional feature.