There is no such thing as total time without a classification of that time. Your reference to SIC indicates that you're an F/O; you're logging total time, but only part of it as SIC? The rest is simply recorded in an invented category? What's the regulatory or legal citation for "heavy crew" time? It sounds like flight time that doesn't actually fit a legal definition is simply thrown into the imaginary category to tidy things up. PIC/solo, SIC, instruction received (if not loggable by other means) and FE time should add to total time for a given line entry.

Were you assigned as SIC for the duration of the flight? Does your company record reflect the duration of the flight? If a regulatory violation occurred during that flight, would you have been subject to enforcement action as an assigned member of that crew? If an event occurred requiring an ASAP report, would you have been subject to filing it as a member of the crew (one files, all file)?

If you flew a 11 hour trip and logged 8 hours of SIC, is the other three simply existing in an imaginary logbook category ("heavy crew") and shown as total time? How can you have total time if it doesn't meet one of the requirements to log the time?