Transferring from FM to IM after intern year

I have an opportunity to transfer from an established, well respected inpatient heavy FM residency into a new internal program after my intern year, and I am trying to make the difficult decision to switch. I have been doing well in my intern year but have decided I want to lean towards inpatient medicine as a career. If I made the decision to transfer, I would have to repeat intern year with an unknown amount of credits transferring. I continue to imagine subspecializing after residency but am having a hard time making a decision regarding my career path. I have already discussed this with both PD's and the opportunity is open if I want to pursue it but would have to go through ERAS and the match process still. Has anyone made a similar switch after intern year? I would be interested to hear thoughts from fellow residents around the country.