Hey,

That's certainly up to the ToS and expert. They may choose to take the PDF/SlideShow beforehand to prep for the call. If you are providing the clarity, that may be fine. Indeed, I often ask for a certain amount of conceptual clarity so I don't spend too much of the client's time and money during the call.

However, to ask experts to do any work on it, or for oneself to ask an expert for clarity before the call is, I'd argue taking advantage of the expert's time. It's entirely possible for unscrupulous clients to get the clarification they need before a call and then never take the call, thereby getting the service for free. It risks leaving the experts out of pocket, potentially twice, if they've given up other work to take that call. It's why Clarity as a platform, exists.

Hence, as both a matter of safety and respect, most customers should not ask to get any clarification without paying for it. Most experienced experts who have been in this game for a while will be aware of such risks and sensibly won't offer clarity without payment for it.

I hope that helps and best of luck for your session!