Hey,
If Squarespace doesn't cut it for email forwarding like Google Domains, check out ProxiedMail. It's pretty slick for setting up wildcard email forwards like *@mydomain.com to your Gmail. Basically, it forwards all your emails without needing to set up each one. Pretty straightforward and could save you the hassle. Check article about forwarding https://proxiedmail.com/en/migrate-emails-from-domain-to-another.
Might be just what you need!