From the perspective of the G4M crew, that is fire and forget.
The Ohka was basically a crude, cruise missile that made up for the lack of technology by using a human as a guidance computer.
The only, even remotely viable, method I can see to add such a thing would be thus:
The G4M pilot pays no perks and loses none should he be shot down. The Ohka pilot pays the perks and the only way to get the perk price refunded would be if the G4M pilot lands with the Ohka still attached. If the Ohka pilot dies, he loses the perks, which means if he is successful, he loses the perks.
Yes, it does make your perks vulnerable to a G4M pilot who decides to grief you.