I use AI tools like Chatgpt. Give it the cloud formation json file and ask it to convert to SAM all the time. In my case i have to clean up some stuff, mainly env vars in CF that get converted into the SAM file because I usually create a SAM config for local testing and emulation of serverless components on my machine so I hard code those values, mostly with stub values. But if you don't need to change your vars from CF to SAM I think it's works pretty well for conversations back and forth.