Yes. A configuration with no message body access at all is fully supported.
By Avik Ghosh, Managing Founder, illuminis
RelationLens finds contacts from message headers, calendar invitations and saved contacts. None of those require reading message bodies, so a configuration with no body access at all is fully supported.
Some customers turn on signature block reading to capture job titles and phone numbers. It is a separate permission, off by default, and bodies are read in memory only, then discarded.
See RelationLens.