I wrote a blog post on the dual speed post processor here. There's a link to download the program in the blog post.

Here's video of Arrakis drawing a pattern at 200 mm/sec with edge speed at 500 mm/sec. This particular pattern doesn't have a lot of edge motion, so the dual speed operation doesn't really speed things up a lot, but it makes a big difference in other patterns. Yes, it's pretty quiet...

I'll be shooting more video, so as they say on the interwebs, "smash that LIKE, and hit SUBSCRIBE"!