Not only is there no radius given, but this bit actually looks off center. You would need to define the center line and measure to the profile side to get the offset.
I would be on the phone to Amana support-they should be able to help you out.
I'm kind of curious-how long is the CEL (cutting edge length) on the insert? since you are cutting 3/16 plastic (Which comes in slightly under at .177) do you have to go far into the table to get the shaped edge?
I can tell you that the insert itself must be seated exactly right in the mandrel or you will have problems. I have one of their insert v bits and it's a noisy son of a gun and doesn't do the job as smooth on acrylic as traditional carbide tipped tools.
If plunging I would ramp and lead in. I plunge into acrylic at .25 ips and keep the speed down (Don't recall my speed on thin material-haven't cut any lately but for larger part and a smaller bit I would likely hit 1.5ips to start and edge up from there to tune it if I was doing a lot. That's with an Alpha and 5HP spindle-Doesn't work the tool to hard but results in a cleaner edge than moving faster.