Forgive me for saying this but your response is classical whitewashing. Its always a nice convenient answer to say oh he was so influential and the other rabbonim had no choice. In fact I believe that’s the excuse why so many gedolim addressed R Kook Zl with such high esteem. Same excuse oh he was so influential that they had no choice. (As if being the chief rabbi of so0me third world backwards non country was so influential)
Here is the truth, R Aron would never have sat down with a true kofer or apikoros no matter how influential they are. R Aron was not a push over or one to compromise He was pure. And in fact he didn’t sit down with anyone in JTS despite the fact that Rabbi Sol Liberman was a genuis and knew kol hatorah kula. (He was also the chazon ish cousin) Furthermore, as I noted, R Aron asked him to give a shteler to one of his talmidim in YU. If YU is complete kefira how can R Aron do that? Its also well known that the two families were close too.
(Side note, its funny how you quote R Isser zalman zl all of a sudden. You do know that he was very close to R Kook Zl. And his own son became head of hesder after R Kook)
Bottom line, yes R Aron was very mad at R JB and did not hold of his approach. He was very vocal and sharp. But he didn’t mean what he said lieterally. He still held him in high esteem. Thes excuses that oh he had no choice because he was inlfuential, I just don’t buy them