Rated 4 out of 5 stars

Nice extension and I love it. But there is one issue about the time stamp in Reply and Forward. It looks to me that SmartTemplate uses the sender's local time instead of my time shown in Thunderbird. I tried all date formats; the results are the same. Other than this, everything works fine with me.

@jeroentje123
Try to check "Use instead of standard quote header"; I believe this will take care of it.
If you're using <br> in your setting, be sure to uncheck "Replace new-line with <br>"