Location of Particle Illusion Standalone Cache

Where do I find the cache, and how does one delete unneeded renders, etc.?

There is no external cache – PI just caches calculations in memory.

It doesn’t create substantial external data files.

So - other than exports, obviously - there are no remnants taking up memory/space?

Unless there are emitter libraries that you don’t want – those are the only things taking up drive space.

Locked emitter libraries are found in the following folder:

Mac:
/Library/Application Support/BorisFX/EmitterLibraries

Windows:
C:\ProgramData\BorisFX\EmitterLibraries

The unlocked (editable) emitter libraries are found in the following folder:

Mac:
/Library/Application Support/BorisFX/UserEmitterLibraries

Windows:
C:\ProgramData\BorisFX\UserEmitterLibraries