If Romulus 2 has to follow the same cast and develop the story further with the prequels then I would really like to see Rain and Andy stumble upon the abandoned Covenant, and we can see what happened with David and all his colonists he could experiment on.
I had an idea for a fan story of the son of one of the covenant passengers becoming rich and using a drone to scan the region of the universe where the covenant was last seen in hopes to find his missing father and then hiring a rugged crew to take him there. Once they got there they find the covenant abandoned in orbit around a planet but clearly signs of something going wrong. Which leads them to track a shuttle that departed the covenant and is down on the surface. When the crew goes down to the planet below they discover an ancient civilizations ruins, using a lot of the ALIEN concept art from Giger and the Egg Silos. They go inside one of the silos and find the skeletal remains of the passengers all laid out ritualistically, with a torn to shreds David at the center. The android they have with them plugs into David's memory and is able to see his findings. This is where we see a flashback sequence of David doing his experiments and going to the planet to study the Engineers/Jockeys. In this sequence we have David admit his 'protomorph' was based off the engineer blue prints, we see the engineers modeled their equipment and came to learn everything they knew from the Space Jockeys. We learn of the different strains of the black goo, and how the Jockeys were using it to seed worlds long before engineers but as their species was dying out they wanted to pass that knowledge onto their "children". Anyways, the crew stumbles deeper into the ruins and finds an underground city but the Aliens David created awaken and attack the crew, eventually it would lead to a boss battle where we get to see an Ultramorph emerge from its slumber (from one of the space jockeys). Had this cool imagery in mind of it blending in like a statue in the background and then it begins to move and all the normal 'aliens' slowly begin retreating even though they have the crew surrounded, and the crew doesn't notice the ultramorph getting ready to strike in the background.
Anyways not sure how I got on that tangent but figured I'd share
probably would have been better posted in the fan section