What is your idea 'enough evidence'? Do scientists have to gather up every possible reverse transcription gene in the known universe and test them?
In principle, anything can happen. Specific cosmic rays can hit my desktop's memory/CPU in such a way that my computer will display a giant smiley face for the next 10 seconds. After all, cosmic rays are known to corrupt computations in plenty of other contexts.
I can even propose more than 1 possible pathways for that to happen!
For sure there could be a more practical way, but even if that's the only option well ... science is rigorous, man. Hence why we still have the theory of evolution and the theory of relativity. If you don't like it and wish to go back to "just believing" ... well, good luck, we won't miss you.
No, there isn't; “mRNA chromosomes” aren't a thing. The comment you replied to made as much sense as “the server rack isn't duplicated on the hard drive”; there's no evidence of it happening, because no possible real-world event corresponds to those words.
Those are peer-reviewed published papers ... and you chose to ignore them? Laughable.
I'm not saying it does happen, neither am I saying it does not happen. There's not enough evidence, that's it. Why is that so hard to grasp?
And there's evidence of it happening in plenty of other contexts, so one wouldn't be crazy to believe that at least, in principle, it could happen here as well.