getStacktrace on getId should be replaced with a real method, the stack trace check, is running on more methods.

pd: there is any side effect removing the packet check? i couldn't see a difference at all. on 1.8.3

Now the method is replaced with a proper API call for Java 9+. I will add an option to remove the packet check, as it's probably not needed for the most (unless you have holograms that teleport really frequently).