Periphery outer ring thoughts ?

My experience has led me to believe, using my two different tt designs that using an effective mat without a center clamp/weight let's the music becomes free with greater inner detail. Aforeunnoticed small details are heard. Bass sounds full, more real like it does live. 

@billstevenson   I made my own that fits the Technics, a constrained sandwich of stainless steel/acrylic/stainless steel.  It only weighs about 1/2 pound, but it is enough to ensure good contact with my acrylic mat., in combination with the center weight.  It's handy to have access to a CNC shop!

@jbrrp1  Methinks there would be a market for your creation.  I know I would buy one.

Yeah, Ralph Karsten was encouraging me to make more (he'd like one, too!), but I am busy enough running a company.  And I think the cost would get high, in the end, too.  It is the perfect vanity project, though.  My employees humor me with my nutty audio passions...
The design was inspired by one that had been marketed for awhile, but was discontinued some years back.  I don't recall the name now, though.

Aside from flattening the record and treating resonances, I like an outer ring for the added mass for extra speed stability.

I had an outer ring that would stick to the platter and thus be difficult to remove and put back. I realized this was because my turntable was being warmed by my amps, and the heat expanded the plastic platter more than the metal ring, causing a tight fit. Notably, when cool, the ring was easy to use.

Obvious solutions were to move the amps away or bevel the inside of the ring.

I was able to use an Expressimo autolifter by reversing it and placing it at the rear of the arm where it would be triggered by a thumb screw on the counterweight.