TL;DR
Is it possible to specify a trench surface to be created at flowline, rather than bottom-of-pipe? (using the utility module)
More context
By default, the utility module in TBC creates trench surfaces at bottom-of-pipe. In reality, pipe types and thicknesses often change a few times during design, ordering, and/or construction. It's not always practical or effective to keep up with the changes that may occur here.
On the other hand, utility flowlines are much more predictable. Flowlines (inverts) are always on the plans, always in the original design, and can always be followed by the crew, regardless of changing pipe thicknesses or bed material.