Particle Playground inconsistent results

I’m working with Particle Playground the most heavily I’ve ever used it, and using it for some fairly unusual purposes (essentially layer instancing).

It works fine overall, but I am noticing some significant inconsistencies with the results I’m getting when I preview a comp versus what I get when I render out the whole project. In particular there seem to be far fewer particles/instances being generated in the full render than there appear to be when I preview. There’s a lot of randomness going on so it’s hard to really quantify, but visually this definitely seems to be the case.

I’ve monitored many of my renders and AE does not appear to be running out of RAM -- the highest I’ve seen the RAM use so far has been about 80% of my 256Gbs.

Most of my experience with particles has been in 3D (Maya specifically), and I know particle systems are quirky, but this seems to be a consistent problem. I know Particle Playground is super old, though I’d never realized quite how useful it can be til this project. But can anyone throw any light on this?