I guess you don’t care what Pope Pius XI said in Mortalium Animos that I have now posted at least two times.
These sorts of conventions or meetings CAN NOT be approved by Catholics. St John Fisher would not have approved this interreligious conference.
I'll see your St. John Fisher and raise you Pope Pius XII. He attended and addressed many meetings of medical professionals and researchers, doctors, nurses, midwives, etc. to discuss all aspects of medical and moral responsibilities. These were not exclusively Catholic groups, and were addressed as well by non-Catholic speakers both in scientific and in ethical aspects of their work --- whose contributions Pope Pius was aware of and appreciated.
He interacted with members of scientific conferences, both teaching them and learning from them --- and not all were Catholic.
Pope Pius XII not only did not bar such meetings with non-Catholics, but positively encouraged Catholic participation. He never suggested that the contributions of non-Catholic speakers were invalid; on occasion he quoted them.
Kind of like Catholics and non-Catholics meeting to think, speak and work together on the defense of Marriage.