Fleib,
Speaking of assumptions.....I'm assuming that you don't actually own a
periphery clamp as I do...❓
You are probably correct in that the use of one together with a centre clamp/weight applies pressure more evenly across the record/platter interface.
However I have found that the sound quality is deleteriously affected if the clamp is used with any pliable platter mat.
When used with a solid mat (metal, glass, plastic) or no mat at all....the peripheral ring does iron out the three seriously warped records I own whilst appearing to have little to no affect on the sound quality.
When used with a compressible mat however, like rubber, felt or leather...the peripheral clamp on my turntables, manages to suck the 'very life' and essence out of the reproduced sound...😱
I am not saying that thin suede mats (because I have found it critical to always have the 'cut' suede side rather than the tanned leather side facing upwards) are the answer to every platter on every turntable...👀
It didn't improve my Raven AC-2 when placed on the copper-faced platter nor did it improve the sound when placed on top of the Micro Seiki Cu-180 platter mat.
I think all these things are system-dependent but as I started this discussion topic within a Thread by saying.....the cost of trying these suede/leather platter mats is small enough (for the possible gains) to warrant experimentation....😎