Hi, thanks for your rating. I'm sorry that you are apparently having a performance problem.
For me, opening the popup usually takes less one second.
To troubleshoot this issue in more details, we'd need more information about your system (i.e. what OS and what Firefox version do you use?). It would be glad if you could open an issue on https://github.com/rugk/awesome-emoji-picker/issues/ and fill out the details there, so we can fix this problem in the next release. Also you can try changing the options (e.g. the emoji style) to see whether this improves the performance.
Let us know if this helped by adjusting your voting. Apart from that, if you have any other ideas or issues, feel free to get in touch.