Everything goes to support@trylath.com. There is no ticket portal and no phone queue, because there is no support team to route between — Lath is early, and the person who answers is the person who wrote the thing you are asking about.
Questions before signing up, problems with an account, billing disagreements, press, and anything about this website. If you are not sure it is the right address, it is — there is only one.
Same address, with SECURITY in the subject so it is not read in order. Please include what you found and how to reproduce it. What we commit to in return is on the security page.
A reply within two business days. That is a description of how this currently works rather than a service level — Lath has no SLA yet, and saying otherwise would be the first thing you could catch us out on.