Custom email domain: threat model & pros/cons?

If I were to use a custom email domain from say Cloudflare, and connect it to my proton/tuta accounts, what privacy/security am I loosing? What I could think of: * the domain could be seized if I don’t use my legal name, so I will be locked out of accounts * correct me if I’m wrong, but it seems there is an easier chance to do MITM attacks for it? * potentially lower privacy since there are paid services to extract whoami from domain registrants I could really benefit from easier email transfers to a new email service provider (for example, I’m way too invested in proton ATP, and it’s really hard to swtich), but I’m just trying to make a more informed decision