Periphery outer ring thoughts ?

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.

According to VPI, their motor is up to the task of spinning the platter with the outer ring, but if it's a concern, it's easy enough to give the platter a little spin before you engage the power to the motor.

The weight concern to me is more about distribution.  You have to have some clearance built into the engagement interface of your ring (due to the variation in LP outer diameters), and that allows for eccentric placement - - in fact, challenges you to do anything other than place it with some eccentricity (perfection never happens).  With the Technics' powerful DD motor and servo, I have no real fears of it being much affected by an uneven weight distribution.  But with a low-power belt drive TT, I wouldn't rule it out as an issue.
I have encountered enough outer diameter variation that I am contemplating making another ring with a larger clearance to deal with the "super sized" ones.  It's an issue.

There is a balance between the weight (mass) of the platter and the torque of the motor. On some tables adding mass to the platter with worsen wow and flutter. It does not matter how tough your bearing is adding mass will always speed up wear. If you have a suspended turntable it is a total non starter as you upset the balance and tuning of the system. Reflex camps are much easier to use than peripheral rings and press the entire surface of the record into the mat and not just the periphery. Vacuum remains the best. The compressors used are very reliable and quiet. The best system for the money is handily Sota's. 

I do not find a reflex clamp sufficient on its own, as some records don't simply respond flat.  Just tap them and you can hear the "play" and opportunity for vibration mischief.  I would agree that a well executed vacuum system is ideal.  It's too bad my SOTA Cosmos didn't sound as good as my new Technics...