The short answer to the question is: Yes taking this job would hurt your chances to get hired with a major airline.
Think about it. You will be flying piston multi-engine airplanes. Piston multiengine time is only useful for getting hired on with a regional. You are already doing that. To take this job would be a step back along the career path.
An airline recruiter would take a look at your resume and ask why you chose to take a backward step. In my opinion this would indicate to the recruiter that you don't really know what you want to do, or are not committed to you career goal. Not a good thing for a recruiter to think about you.
If the majors are your ultimate goal, then stick with the regional.
Think about it. You will be flying piston multi-engine airplanes. Piston multiengine time is only useful for getting hired on with a regional. You are already doing that. To take this job would be a step back along the career path.
An airline recruiter would take a look at your resume and ask why you chose to take a backward step. In my opinion this would indicate to the recruiter that you don't really know what you want to do, or are not committed to you career goal. Not a good thing for a recruiter to think about you.
If the majors are your ultimate goal, then stick with the regional.