Hi Jonathan
I think this is a great idea and something I'm also thinking about implementing on client sites.
I think you could check with Acuity directly if you can prepopulate fields by appending them in the URL.
You might be able to pull some useful fields from the Confirmation page, which you can see in the Settings > Advanced > Code Injection section:
{orderId}: The unique ID of the confirmed order
{orderSubtotal}: The subtotal of the confirmed order
{orderSubtotalCents}: The subtotal of the confirmed order, in cents
{orderGrandTotal}: The grand total of the confirmed order
{orderGrandTotalCents}: The grand total of the confirmed order, in cents
{customerEmailAddress}:The customer's email address, as it was entered in the "Billing Info" section
Maybe you can embed the link to the scheduling page and append some of these strings above to it?
Would love to see how you get on, great idea and very useful in current times.
Catherine