+1 on street tires only in 'Stock' class.
ST classes were borne out of street tuner parts on an otherwise stock daily driver. Rcomps do bring a big $, may wear longer (much debate here as the longevity may make $$ work out, but DILYSI has data to show different)
While were at it, lets get rid of the shock allowances also in stock. No remote rez shocks, maybe only single adjustables. Perhaps no sway bar change at all...
As others have pointed out, fast drivers will still be fast. However, maybe Natn'l tours will enjoy larger turnouts and higher competition from unknown 'hotshoes' not in a place to spend $$ on r-comps. No biggie if a competitor wants several sets of ST tires, thats their choice.
That is, if SCCA really wants to expand its membership, there have always been funny stories and rumors of the opposite.
Eric G