Thank you very much for the valuable reply and efforts to explain things.

On point no. 2, I find Mr. Mariog's thought convincing in the sense that VAL could be measured and reached so long as the transition point on AG (preferably with an anchorage) is defined as a reference point which is fixed. With other design conditions, VAL could be worked out manually or by Caesar.

I shall highly appreciate if the below point is clarified :

If the UG pipeline takes turns, changes in elevations and such major directional changes occurs as always expected in pipeline running several hundred KM, then still complete pipeline modelling is not required ? Please clarify.
In such long distance pipeline, Suppose pipe comes up AG after few KM run and further goes UG and this happens at quite some places for pressure boosting or other control requirements, if any, than do we foresee complete pipeline modelling and along with any thrust block requirements ?