You really can't compare DA speeds to rotary speeds, so there is no point to such a discussion.
P085RD
DA - start off at speed 6 (maybe a little slower on a more powerful Flex – I haven’t used one). Use firm pressure to assist breaking down the polish and then reduce speed to about 4 and lighten up the pressure. On a DA I still wouldn’t call this jeweling, but it should improve the quality of your finish marginally.
Rotary – An all together different technique. P085RD doesn’t need any more than 1200 rpm to break it down. You need to learn the Zenith technique which is basically start off slow (600) to spread the polish over your work area, gradually increase your speed as you progress through increments of speed to 1200 rpm all the while breaking down the polish. Then you need to do the same on the way down, lessening the pressure on the polisher as you step down through the speeds until you end up at about 700-800 rpm.
There is a thread over on Detailing World titled “Machine Polishing By Rotary Polisher” that explains the ins and outs of the Zenith technique. Don’t expect to perfect the technique in 5 minutes as it takes hours of practice to get it just right.
I will add that if you are prepared to learn this technique, you’ll probably never go back to a DA. Learn this technique first before you even attempt to cut paint with a rotary. Once you know this technique then using a rotary for more aggressive tasks will be easy.
In other words, don’t start learning the rotary by attacking some old panel from the wreckers. This might sound controversial, but most of you already have the perfect panels to start your learning curve using a top quality rotary machine. If you are an experienced DA user then I assuming you have your vehicle in pretty good shape. Turn your new rotary loose on your bonnet (hood) using P085RD on a black or blue pad. Sounds a little drastic, but it is not when you think about it. P085RD is about the least aggressive polish out there. Couple that with a zero cut Black or Blue pad and common sense says you really can’t do any damage to your paint. If you are paranoid then start with smaller 5.5” pads (less speed) although in my observations, new users generally find it is easier to control 6.5” pads as they are easier to keep flat. Take the following precautions - tape off adjoining panels, just in case you do slip and tape off anything you don’t want to polish.
One thing I will guarantee is that it is far easier to learn how to use a rotary on a perfectly prepared surface (like your DA’d hood) than some piece of oxidized junk from the wrecking yard or panel shop. The junk panels still also have their users, but not for learning this technique. If you are still skeptical and insist on using a junk panel, then first spend some time on it with your normal DA routine. The main idea is to make sure your first rotary experience is an enjoyable one and not the nightmare many users find.
I’ve been thinking about writing up a guide for new rotary users, so if there is any interest here let me know.