PLAs are weird because they are basically blueprints. So, actors actually can move, it’s just that instead of treating 100 of the exact same mesh as individuals, you treat them as mostly identical, save for translations (which are the only way to adjust them).
No, you cannot include decals. They aren’t supported. I’ve tried, failed, researched, and confirmed.
Also, PLA-ing allows for distance culling, which is a GODSEND.
You may want to look into it, but you can define when members are culled. Great for hiding large or obstructed structures that can gobble memory.
More… learning.