Watching NL's and TTEdge's videos about pendulum and reverse pendulum serve, I have tried to improve those two serves of mine in a two hour training session yesterday. I've spent 40 minutes only serving these two serves. I must admit, with my elbow much higher than I was used to, I can generate a lot more spin with my pendulum serve as before. After the tenth serve or so there was an improvement in amount of spin compared to what I have done the last years. That was amazing!
As for the reverse pendulum serve, I was quite satisfied with it over the last years, however, it was never close to being as good as a very good player could serve reverse pendulum (my USATT rating would be >2000). With the videos provided here I know my faults now and tried to improve this serve yesterday as well. It did not work out well at all

I just can't end my motion directed to my opponent instead of to the side. Changing that will be hard, I have to somehow erase my years old automatism. However, with the improved movement it was easier to serve reverse pendulum parallel into the wide forehand. At least one sense of achievement, although still far away from where I want my reverse pendulum quality to be. I'll keep trying! My goal is to have a much better reverse pendulum serve as before by the new season's start, that is September 2017. Enough time!