Place and 'Accept' Button in HTML for Quotes (like Pay Now button on invoices)

In designing a new quotation template, it turns out you have to send a 'statement' link for customers to be able to accept it, AND an 'invoice' link if they want their quote as a PDF - which overwhelmingly they do nowadays. That's daft isn't it, and confusing for many customers?

In an ideal world what they would really like is a PDF quote with a yes or no button. But know this will cause several issues, and be more difficult to implement, it has been suggested that an 'Accept' Button in the HTML used in generating the quote email would also do the job, and be far easier to implement.

So, why not place an 'Accept' (and a 'Reject'?) button in quote email's html?

Neil