I have some RT1176's in my "to try" pile.

The big thing holding me back was that their crypto accelerators were all locked behind NDAs (a dealbreaker for F/OSS work) while the ST ones are documented in the freely downloadable datasheet you can just google up.

But I did find some third party wrapper libraries that seemed to be able to use the crypto registers so it might be possible to figure things out from that. I haven't tried yet.

The other issue I had with the RT is that they lacked internal flash so PCB complexity is slightly higher than with a STM32.