Fifty years ago "experts", perhaps like you, would have denied that viruses could integrate into the DNA of cells (of any type) and then they found Phage Alpha. Yes, I know that phages only infect prokaryotes. After that they found retroviruses and LINE1 elements in our DNA. So, that deals with the integration of RNA into normal cells. It happens, and you said so yourself above.

So now we are only arguing about whether or not Integrase is the only mechanism by which random DNA introduced via LNP transfection and jacked into the nucleus via an NTS can integrate.

In my opinion, we know only a tiny amount about these processes and anyone who says "there is no other mechanism by which these random pieces of DNA can be integrated during meiosis" is seriously ignorant.

We already know about template switching during transcription. How certain are we that during meiosis little pieces of DNA cannot be incorporated. We know there are molecular mechanisms to cause DSBs and to repair copy mistakes ... and from an evolutionary point of view the frequency of the introduction of foreign DNA into nucleus has been quite low compared to these modRNA vaccines. They introduce orders of magnitude more DNA than even DNA viruses can, so I suspect there has been little selection pressure to guard against foreign DNA fragments ...

Perhaps, as an "expert" you can provide arguments against that view.