Adjusting Suspension Seat post?

I just picked up my new Cube with what I believe is the RFR suspension seat post.
I wanted to set it up softer than it came.
There is a plug at the bottom of the post which uses an metric allen key. Turning it either way does not seem to make any difference at all. Could this just be a plug that needs to be removed to get to the adjuster? I am not wild about removing it completely.
My understanding is Cube has two seat posts with a different elastomer in each of them and it can be adjusted. Am I missing something? My weight fits right in the range of elastomers offered in both Cube suspension seat posts. CN