Hello Coking Committee
Yes, many cokers use HCGO as drum vapor line quench and it works well. In fact, I believe it works better than LCGO because the higher boiling point keeps the oil in a liquid form and promotes a washing effect of the piping walls. LCGO can quickly cool the drum vapors but solids can still accumulate along the wall. IF your line velocities are very, solids could be washed away by the vapor but less likely.
However, the even better drum vapor quench medium is blowdown tower bottoms, if you ask me. It is a great way to recover slop internal to the unit.
Curious, how many people are in your committee and where are you based?