I would also like to use Mingling to find the RNG but it is a lot more random. When I played, I had to leave my DS all night (about 8-12 hours) and only receive 1 or 2 aliens (sometimes 3-4 or none at all if I'm lucky). Maybe it would be easier (it would take less work but a lot more time) but I will need to grab an alien (or more) first to get the addresses I will need. Then I can set up a lua script to monitor these addresses and pause when I grab one. Just restore to an earlier save state, wait until it reaches a few frames before, and I got an save state for comparison. Then I just need to rinse and repeat until I get enough save states. I like that idea so I will give it a shot.
No
When I played TWEWY long ago there was a trick where you could force Aliens to appear if you have access to a Wii. If you have the Wii send a DS demo, TWEWY will count the signal as a alien. I don't know if you still need aliens to appear, but if so I hope this helps.
Regardless, good luck on the run, I'm looking forward to anything put together.