Just treat them like the good old landeds from EU/EW/LW1. They have aliens you would expect to see a month later. Do the same thing with infiltration. Great March supply raid? Yeah by all means go in at 0% with your LCPL and CPL and ballistics...by the way most pods will have a muton or a mec in it! Bring in the codex's earlier, bring in the gate keepers, and beserkers earlier, BRING ALL THE STUFF IN EARLIER!!!
Add in a command pod, that has an officer advent and works the same way as command pods in LW1. You have the big baddy...and ALL his friends if you decide to fight him before clearing the map.
There are two big issues with 0% raids right now is the resources they provide allowing you to snowball.
- Resources:The provide an extraordinary amount of resources, and lets face it the difference between killing 30 advent and killing 40 or 50 advent is pretty minimal when early on they basically are just a bunch of troopers, and later it is stuff you are already equipped to deal with. That effectively represents 20-40 alloys (50-200 supplies if you sell corpses) for basically sitting in over watch for 2-4 turns and cleaning up anyone that survives the hail of bullets.
- Passive play: It pushes you into really passive save play styles, just sit in a corner blow everything on the first couple pods then let sharpshooters and OW kill the rest of the pods as the trickle in.
- It actually makes the mission harder. Currently increasing the number of enemies doesn't really make it harder, since you just sit in a hole the whole mission and you really are only fighting what is in front of you and in range of your soldiers, at most that is maybe 10 advent, with the threat of new ranks replacing them as you kill them. But realistically outside of a potential swarm early...which you just blow up with liberal use of explosives...you are only fighting one pod at a time, you probably kill a couple enemies before the pod is in range, and the pod has to oftentimes dash through OW to get into range meaning you never really take shots from the enemy. So adding more enemies on a mission doesn't actually increase the difficulty, when it is really just like 8 mini missions of 8 troopers vs a squad of 10. Adding one or two stronger enemies per pod though, means you are not wiping out the pod, you either kill the weak troopers and have something scary, or kill the scary thing(s) and still have the troopers. From a game perspective, replacing 1 trooper in an existing pod of 8 with a muton, is more dangerous than just adding another pod of 8 troopers. That 5th or 6 pod of 8 with a muton or two is far scarier than your 8th pod of 8 troopers. So adding a harder enemy makes the game harder FASTER than just adding more enemies.
- Reduce the resources BUT reward the difficulty in a non-snowballing way. From a straight monetary value 9 (8 for the new pod, 1 for the trooper the muton replaced) trooper corpses are worth more than 1 muton/mec/beserker/ANYTHING corpse. A muton corpse doesn't really sell for much more or render into much more than a trooper corpse let alone 9 that they are effectively replacing (significant reduction in monetary value of doing a 0% raid) BUT if you take them out now you did get a reward, you get to do the autopsy research a month or so earlier, not game breaking enough to snowball, just a small advantage IF you want to invest into it (you get it early so it would take longer to do the research) compared to say 3 laser weapons or 3 suits of predator armor that the extra 10-20 trooper corpses just bought you. So going at 0% isn't going to yield much more in regards to rewards for completing it.
- Increases options as far as research paths. This ties into pushing up corpses earlier. This gives you a boost regarding specific tools, are better grenades worth delaying better armor? I don't know maybe in one play through that answer is yes, maybe in another that answer is no. and you get those kind of questions every single month (just like you did in LW1 when you got a corpse a month earlier than you other wise would have).
- It increases squad load out options. Currently when you just throw more and more enemies onto a map it forces you more and more into a corner. You can't play more aggressive load outs since odds are you will pull more pods, and if you are going to hold back that assault/flamer/sword swinging shinobi for 2/3 of the mission, why not bring someone with more range? If you reduce the number of pods it opens up the map more, it reduces the chances of mass activation when playing more in your face classes...which is good because if you are fighting harder enemies earlier you are going to want the power that some of those close range classes/specs bring. Besides who doesn't like shotgunning or slicing advent in the face!
Then you have the addition of a command pod with an ranking advent officer (higher health and more armor) at anything below 100% infiltration. Basically they were in the area to help secure and clean up the mess initially (REBEL SCUM!!) then once things seemed in order they moved onto other more pressing issues leaving the low grunts to pick up the spilled boxes.
TL;DR The easiest fix for 0% supply raids is just increasing the quality of the troops you face more so than the quantity (why not both!) this still rewards those that attempt to do them at lower infiltration %, through getting their hands on technology a little earlier, while not being super snow bally from a resource perspective, AND providing heavy dissuasion for trying to run them at low % infiltration.