MDG,
If you read through my posts, you’ll find that I demonstrated that it’s obvious even in the teshuvos in Igros that R’ Moshe meant for the p’sak to be applied b’shaas had’chak.
I am familiar with R’ Forst, and I highly value his opinion (which might be a chutzpah for me to say, but in context of people who don’t know him, I hope it’s ok).