I saw Search for Spock on BBA America Friday night. I haven't seen it in years. I know people like to hate on it, but I don't think it's that bad. Of course, it's a step down from Wrath of Khan. I think people would have been disappointed by anything that came after it. The biggest problems I had with it was that Kruge wasn't a very good villain and how they retconned Kirk as the head of the Genesis project and put him in the Genesis overview video so they wouldn't have to pay the actress who played Carol Marcus to reuse the video from Wrath of Khan. The whole movie is worth it just for the sequence where they steal the Enterprise. It was nice to see everyone get to do something for once.
I don't think that was technically a retcon.
Kirk, in Star Trek 2, is fully aware of the Genesis Project and what Dr Marcus is up to, and apparently that's not because she or Chekov told him, but because he was a bored Admiral who googled one of his old girlfriends one day using his work computer, and he watched her project proposal video, which he was technically allowed to watch, because he's an Admiral, and his security clearance is that good. And it's not like Dr Marcus' proposal was that big of a secret, because she was shopping it around, hoping to get funding, which she got by way of Captain Terrell and the USS Reliant.
Khan dragged Kirk into the situation after Chekov namedropped Admiral Kirk, as apparently Admiral Kirk has enough sway that he could insert himself into Project Genesis any time he wanted, and steal the whole thing for nefarious purposes (or at least, most people seem to believe he has that much power). And because Khan namedropped Admiral Kirk, Dr Marcus called Kirk to complain, and Kirk already knew enough to know what Genesis meant when it's Dr Marcus asking about his interference with it.
So Kirk looped Spock and McCoy in on the subject, by using his security clearance to show them her proposal video, as he's apparently allowed to do. Then a bunch of fighting and stuff happened.
Around the start of Star Trek 3, Kirk is
making a report to Starfleet about Star Trek 2's events, and he begins his report by saying that the first thing they need to do is get up to speed on Project Genesis, which Kirk summarizes, using bits that he cribbed from Dr Marcus' research proposal video. After hitting "send" on his report, Kirk slowly limps his damaged Enterprise home.
Kirk's report to Starfleet causes chaos, as Starfleet considers the best way to diplomatically handle these events, and the Klingons observe the Starfleet chaos, while at least one of them (Kruge) arranges to steal the source of this chaos (Kirk's report), with the help of his wife, who he kills to ensure the absolute exclusive secrecy of this intel (whatever it happens to be). Kruge interprets Genesis to be a weapon of mass destruction.
As one small part of the Starfleet chaos, after submitting his report, Admiral Kirk repeatedly asked Starfleet over the radio for permission to take over the file on the Genesis planet, but Starfleet went radio silent on Kirk, eventually telling him (in person) that the Genesis situation has shot up the ranks at Starfleet, and now it's very much above even Admiral Kirk's pay grade.
They clearly did it this way because they didn't want to pay the actress, but I think it does make logical sense for the video in Star Trek 3 to be Kirk's up-to-date report of events (which includes an edited portion of Dr Marcus' original video), rather than Dr Marcus' original project proposal video.