I really don't see any complication with Self-Planetfall.
Quote:
Nominate the action for the formation and roll to activate. If the unit fails to activate its arrival is delayed to the next following turn. If the activation is successful, place the formation at the plotted landing zone and determine scatter according to Core Rules 4.4 as if it were a normal Planetfall, including loaded units disembarking up to 5cm. The formation’s action proceeds as normal in all respects from that point. In other words, the formation gets the “free move” from Planetfall placement at the beginning of its action but in all other ways activates as normal. Note: The action is chosen at activation, before scatter is determined. Choose the action carefully as a poor scatter role could render some actions ineffective.
It seems very clear what the intent of Self-Planetfall is.
It is a completely seperate rule from Planetfall and the 2 should not be looked at together.
One roll to activate (identifying the action the formation will take at this point).
Place the Self-Planetfalling formation on the table as plotted at the beginning of the game (determining scatter and deploying transported units if desired).
Immediately carry on with the activation as previously identified.
It all seems pretty straight forward to me.