If you're giving feedback on a SPECIFIC deliverable, please use an appropriate formal communication methodology. When you log something within formal communication (whether it is in an email, ticket, issue or task), you create a clear system of record.
Simply firing off a quick text or chat may be easy for you in the short-term, but it creates a headache in the long-term. How will you follow up and see if your feedback was implemented. How can you perform a proper retrospective? That's why we've included communication INSIDE of our Actions. Check out Profecta to learn more or read our post on why real time may not be the right time for your Product Team.