Transitioning from factual to drama

I'm currently starting off as an office runner in factual entertainment, but I know I want to end up in drama in the long run directing and I'm wondering how far down the rabbit hole I can go before it becomes truly difficult to transition over. I've seen a few PDs bounce back and forth with drama and wanted to know if it's a viable route, as I do enjoy factual and shooting as well. (Apologies for loading so many questions within a question)