warmstart.io is the canonical home — it reads most like a serious software company. The others funnel into it: campaigns, SEO, and clever short links, all warming up the same fire.
It feels most like a serious AI/software company. warmstart.it is clever but a little hacky for a primary brand; trywarmstart.com is excellent for campaigns but not the company URL. Consolidating SEO and signups on one canonical domain keeps the brand legible and the link equity in one place.