I don't understand why it is necessary for the theory to have a 'use'. After all, the theory is to be judged on how well it conforms to reality and not on how practically useful it is.
I meant 'use' as in what it actually tells us about reality. If there is no elaboration on what an 'experience' at the fundamental level is, then it isn't saying anything.
This doesn't mean that there aren't panpsychic theories on exactly what the nature of an elementary monad is - for instance, Whitehead theorised perhaps the most famous description on what a basic experience is and it involves the becoming internally of a direct causal interaction that leads to a spontaneous result.
Could you elaborate on this?