I submitted my extension to Google Chrome. I’ve been through two separate reviews and it went just fine - already published two versions.
Put it into Firefox and it’s still under review.
I’ve been using Firefox literally over 20 years as my only browser. I am a proponent of the browser, so that’s why I decided to include Firefox in addition to Chrome & Safari.
However, the process to have it published is slower than Google and the interface to manage the items is antiquated. I’d love to see both improved as I’ve been a proponent of Firefox and why I decided to include Firefox.