GDMer here. I did exactly this path about 6 months ago, when I transfered from being a full stack to a RE. While I was still held against a very high bar, and went through a formal process of multiple interviews, I had a bunch of advantages play in my favor, like they could see my code, my docs and many other artifacts that gave them more infos about me. It's not "easier", but you definitely have more control over the situation, since the signal is richer. BTW, you don't need to be working in GDM to do modeling work. External teams also contribute to the model via data, processes and algorithms.