> Claude has a different personality and performance than other models for example

This kind of thing amounts to a LoRa applied to your model. There's no reason (apart from potential IP infringement) that someone else couldn't produce a "Claude LoRa" for their model (or, more likely, given the dislike for Claude's writing style, Anthropic could offer a "non-Claude LoRa" for their own models)

I completely disagree with this. What you are saying is that performance, all they need a simple trick and they get Claude performance for free. In that case, why do we see open weight models still lagging?

Assuming you meant this for personality, I’d still disagree but not that extensively. I think personality is nuanced and complex - it can’t be simply lifted and shifted. It’s grown using a meticulous process.