Adding receipts to invoices

Lshwarts

I know this feature has been requested multiple times, but in my research I noticed that receipts can be uploaded and attached to bills/transactions. Would it be possible to associate specific purchases/bills with estimates or invoices so the existing attachment could be cross-linked to the invoice? I helped a friend of mine who has a handyman business get started with Wave and he loves it so far, but he frequently has to purchase supplies / materials for clients' jobs that he adds to the invoice and wants to include the receipts somehow so the client can access them. Or even if he could upload the receipts to his Google account and then paste the link to the pdfs in the invoice so they're clickable by the client?