Phil OliverI do think WJ intended PE as an aspirational target in our philosophizing, a notion of pre-conceptual immediacy that would stand as a brake on runaway intellectualism. He always proposed to defend experience AGAINST philosophy (and other post-experiential abstractions and reconstructions). Is there really such a thing, though, as a recovered experience free of conception? Probably not. But the concept of PE is useful as a reminder that experience in the first instance always precedes most, at least, of our conceptions.
I’ve written a bit about this… https://www.google.com/books/edition/William_James_s_Springs_of_Delight/OonHEQJuyaUC?hl=en&gbpv=1&dq=purity%20of%20pure%20experience&pg=PA79&printsec=frontcover