The claim
PerplexityBot should be handled as a search crawler. Perplexity-User should be tested and controlled at the network edge rather than treated as a normal robots.txt crawler.
What the evidence shows
Perplexity's crawler documentation says PerplexityBot is designed to surface and link websites in search results and recommends allowing it in robots.txt. The same documentation says Perplexity-User supports user-requested page visits, is not a web crawler or training agent, and generally ignores robots.txt because the fetch was user initiated. Perplexity also says crawler-setting changes may take up to 24 hours to reflect.