My first TC -Downpicking speed Plateau

Hi, I cannot seem to increase my downpicking palm muting speed and I feel like there is an issue with my technique. This clip is me at 170 BPM after warming up for at least an hour, but normally I average around 160 BPM and have been stuck there for a long time. I have included slow motion footage at the end of the video to help show the picking motion more clearly. Is there anything in the technique that stands out that I should change or work on? Thank you, I look forward to your feedback!