A small thing, but I was having fun trying to catch them all. But the lowest tier isn't worth any points, so to continue to run stage 0 land is not worth the time and effort. Getting a complete tier 0 collection isn't worth many points, and honestly getting the entire collection isn't worth a ton of points. It's super top heavy on tier 5 illuvials and holos.
I'd like to catch them all, but I'm probably going to have to give up on this as it doesn't seem beneficial to keep running stage 0 maps and finding zero stage 3 illuvials. And apparently no one else is doing this either as tier 0 stage 3 illuvials are worth a fortune on marketplace.
If you want people to try and collect them all, and not just run for holos and tier 5's I'd suggest making it a bit easier to get them.
Make it so that all illuvials in stage 0 land can be caught. I've done a full run and shot down illuvials to see what's inside. Even if you shot every illuvial down there was only a few stage 3 illuvials in the entire map. With twenty five stage 3 illuvials you need to catch, this would still take you a very long time to do.