Joseph,
I mentioned 2 names, Rav Yaakov and Rav Shimon Schwab. I have discussed the question personally with multiple “yeshivish” rabbonim. I am not saying their names because when someone asks a personal shaila, the response is meant for him alone, not for publication unless the rov says so. Rabbonim are often reluctant to publish heterim because they do not trust that the heter won’t be misunderstood/extended. This is why modern written sefarim are always more machmir than what you find when you ask a rov a question personally (and why english seforim are most machmir of all). There are thousands of frum, erlich baal baatim that will shake a woman’s hand in a business situation based on the advice of their rov. You are dreaming if you think that this is anything but a mainstream view.
Mik5,
Do you know that “hefsed mamon” and “hefsed merubah” are commonly used terms in halacha? There are many things that are allowed in cases of loss of money, more things that are allowed in cases of a signficant loss of money (hefsed merubah), and if the loss is more than a third of your assets, even bitul esaih d’oraisa is mutar. Frankly denying the concept of hefsed mamon is much closer to kefirah than using hefsed mamon as a basis for a heter.