I'm in the minority of minorities of those who believe that "David is the [79' film's] Space Jockey" is the only way to finish off the prequel series in a compelling yet non-pandering way. Before Prometheus debuted I wanted the same non humanoid 'elephant men' on 'Giger-world' that everyone else is still pining for. Since then, however, I've come to accept and appreciate the prequels' own merits, mysteries, and admittedly subversive vision. Now fortified by Alien Romulus, the prequels are feeling even more lore-consistent and thematically profound.
That said, I think David has proven to be a remarkable anti-hero, deserving of an implied Promethean punishment (or self-sacrifice): one that might result in the first synthetic to not only to be mutated into the giant space jockey seen in Alien, but to be somehow infused with the derelict, and, moreover, impregnated with a xenomorph embryo in some way...perhaps even giving birth to the first alien queen (seen in Aliens). Furthermore, the genesis of an queen, could be David's way of ensuring the self-perpetuation of the xenomorph (primordially worshiped and exsanguinated by the Engineer race), beyond David's 'lifespan'.
Note that the supposed age of the 'fossilized' jockey in Alien, is purely speculated by the Nostromo crew; so long as the biomechanical mutation is either willingly achieved or forced upon David, a 3rd prequel could plausibly, through that mutation, bring David's corpse up to scale with 79's. This is the only way forward. Love it or hate it, with Romulus included, we are now three films deep into Ridley's personal vision and too steeped in David's experiments, to satisfyingly retcon his diabolical efforts.
