CJ is cool, but the typical warmup it provides doesn’t fit my taste. I think it would be cool to have a custom warmup that would automatically attached to any workout it creates (except probably endurance and recovery ones, where you basically don’t need a special warmup).
I don’t think this is technically complicated but maybe makes the learning curve too steep but for advanced users it would be beneficial I believe.
None of the apps at the moment offer such a feature AFAIK.