Really good work with the project, we may do some work for it in the near future. I am testing it and I have found the following issue.
When sending the email to the customer with the invoice I can see this on my gmail account :
So is not formatting it right on the sending?
Also when I click the link:
it triggers a 502 error
Could you let me know if there is something I could test in order to fix this?
Also Do you have any rough date about releasing the first production version? we are going to go for the v5 but it seems is still under heavy development.