If NEXT_PUBLIC_SITE_URL still points at *.vercel.app, every canonical and Open Graph URL will advertise the old host. Set production env to the .com before you care about rankings.
Leave the vercel.app deployment up if you want, but do not link it in profiles, schema sameAs, or blog CTAs.
www and apex
Point both apex A records and www CNAME at Vercel, then let Vercel redirect to your preferred host. Mixed hosts confuse analytics and dilute brand searches.
