sam: Rav Shachter told me personally 96%, but that’s not important.
“it’s very clear that we have more reasons to add Chumros to a Lav that is Mefurash Bikrah than one which isn’t. I would think that would be Pashut”
Not at all. A drasha is just as much dOraisa as mefurash. Would you be meikil eating Basar bChalav since the Torah only writes cooking and eating is a drasha?
You still haven’t addressed my point that there is NO ta’aruvos on statistical probability alone without vadai issur.
I’m also looking forward to a source for the Rosh an Ra’avad