If you haven’t flown for 18 years and have never been CA, you’re going to have a really bad time. You could be a shuttle commander and you would still struggle. That’s a significant amount of time off. It sounds like the near DEC program you were talking about is a good fit because a true DEC position would be a challenge. One 121 failure and you are pretty much stuck in the regionals/LCCs for life. I’ve seen ex-mil guys fail their checkrides, ex-airline guys fail, Etc. Not saying you will but after 18 years, it won’t be easy.