“In short, I am trying to see whether one can ‘choose’, or at least influence to a significant degree, the conditions of the next jati (in the current bhava) by powerful abhisankhara(s) and thus ‘overpower’ or divert at will the overall blueprint of the bhava..”
Abhisankhara means good or bad kamma. Just one bad abhisnakhara (killing a parent, for example) can change the whole picture instantaneously. Just making good thoughts at the dying moment may not make much of a difference (unless, of course it is a strong kamma, good or bad).
– Furthermore, the bigger unknown is what kind of kamma we may have done in previous lives and are waiting to bring vipaka. This why we need to strive hard to make progress on the Path.
“we always say that Existence or Nature ‘knows’. The thought may arise that since It knows, It is therefore an entity, because to know is an attribute of sentient beings ..”
This is a version of Creator concept. There is “no entity” called Nature. When I say, “ A suitable womb is decided by Nature”, I do not mean that literally.
– Actually, the world operates according to paticca samuppada. Things happen due to causes, under suitable conditions. It may not be possible to sort out exactly why something happens, because there could be multiple causes leading to that.
– When one throws a stone, there is no “entity” out there making sure that stone flies a certain distance. There are laws of Nature (Newton’s Laws and laws of gravitation) that automatically operate to make the stone take a certain path. Similarly, a tiny seed grows to be a mighty tree according to universal laws. A gandhabba being pulled into a “gati-matching womb” is just like that.