The best thing I've heard about Homelander is that he was (at least somewhat) aware, but couldn't leave or do anything to spook off the elites
Firecracker got knocked out
Tek Knight knew about Hughie from the beginning. He immediately catches Hughie bumbling his way through the conversation with his awful impersonation, and the camera cuts to him rubbing the rim of his wine glass to test "Webweaver's" superhuman hearing and instantly notices the lack of any reaction from Hughie. But like with Homelander, he can't make a scene and makes sure to take him away from any prying eyes.
Sister Sage is likely working her own angle. They have some of the most influential and powerful people in America in attendance and Sage didn't hire
any security guards to watch the entrances? More than that, she gives Neuman the speech so she can handle herself then agitates MM to shoot her. This gives her plausible deniability to not help Homelander. She has been surveilling MM since she knows all about his daughter so she knows he'll be at the party.
Sage knows that Homelander is unhinged, and putting him in power is a danger to herself. His Ego couldn't take it knowing she was smarter than him. She gives Neuman the stage (and all the support of the real rulers of America) as part of her plan to keep herself safe.