It is not uncommon. I’ve known several shooters who carried TDA pistols cocked because they didn’t like the DA pull. They would even reholster this way. Well, they tried to until we put a stop to it, but with at least one of them, learning did not occur.
I see it out of forgetfulness often with 1911s, but I have never seen someone willfully reholster an off-safe 1911.
The only “safer” option in regardes to actions is DAO or LEM. I don’t think SFA/TDA/SAO have any humongous safety advantage when proper technique and quality support gear are used. They’re all just different.
You can neither train out, or hardware out the danger, but you can mitigate it to a degree where you are comfortable with the risks involved.