Seamus M. This is a real thing and IMO it's where the biggest impact happens. I've lived this exact hybrid. I was a founding SDR at Atlas (acquired by Remote), where I generated 260+ SQLs while simultaneously building the full outbound stack: Clay for enrichment, Instantly for sequences, deliverability management, A/B testing, the works.
The difference a GTM/SDR hybrid brings is that they understand what makes a lead actually convert — not just how to build a workflow that sends emails. The copy is better, the targeting is sharper, and the handoff to sales actually works because they've been on the other side of that handoff.
Happy to chat more if helpful!