Ok that is was I was thinking but then I noticed the dmcc light and ds30 are rated to have the same amount of flex.
According to Lady Flintstone Flex rating:
Stiff SF45 > DMCC light > TT30 > DS30 Soft
DMCC light has a stiffer base than TT30 due to carbon infusion. DMCC light highback is softer by design but has same material composition as TT30.
The following comment is my interpretation:
TT30 and DS30 base have the same composition but the TT30 will be stiffer by design due to Alpha base (allows more ankle roll). Note, Alpha base has inserts to stiffen flex if desired.