- actually, the limits you're asking about can generally be found by examining manufacturer information, industry information relating to standards, and current limitations for manufacturing fabs..
AFAIK, and I have confirmed this from testing and using them, mini-sd to sd adapters and there kin are just pin-converters, mapping from small to large. As SD and SDHC are pin-compatible, there are no reasons why there should need to be different adapters.