Exclude www from certificate scope — subdomain delegated to third-party SaaS

Hi,

Site: tlmr.netlify.app — custom domain tlmr-avocats.com

www.tlmr-avocats.com is CNAMEd to a third-party SaaS platform (LearnyBox) that hosts our client’s sales funnels. It will not point to Netlify. The apex resolves correctly to 75.2.60.5.

Netlify automatically pairs www with the apex domain, and there’s no option in the UI to remove it. In May this caused the renewal to fail with “Certificate renewal incomplete: missing domains www.tlmr-avocats.com”. A manual Renew certificate has since succeeded and the current cert lists both names, auto-renewing before Oct 19 — but since the DNS situation is unchanged, I expect the same failure to recur.

Is it possible to permanently scope the certificate to tlmr-avocats.com only, so renewals don’t depend on a hostname we deliberately delegate elsewhere?

Thanks.