Lots know the details and they have written letters - all against the Heter.
I guess your point being is that the people that support the heter don't know the details in order to write letters supporting it
I meant here
BTW from my experience by all these rabbonim in Israel they themselves don't look into it personally they trust their חצר but nebach the gabboim are not trustworthy
As someone who was a Gabbi by רשז"א once told me alot of the gabboim are like גיחזי