Best Practices for Managing Secondary Domains in Email Outbound Campaigns to Protect Primary Domain

Hey everyone! Had a quick question on email deliverability and hoping for insight from one RevOps person to another. We’re planning to launch higher volume email outbound campaigns at Agentio through Instantly, using secondary domains. Would you keep those domains in the company’s existing Google Workspace, or isolate them in a separate Workspace to better protect the primary domain and core business email? Curious what you’ve seen work best - if this isn't your domain, could you point me to the right person at your company? Would love to learn more about this topic, and thanks in advance!