with portal not active, emailed invoices can simply be click-and-pay directly from the emailed invoice. No login is required.

however, when the portal is enabled, the link in the invoice now requires to login.

This seems like a step backwards, as it can now take longer to effet payment by clients (cannot find password/lost password etc)

Payment is also not necessarily done by the same person(s) that actually access the portal.

It will be better to allow the option, with portal enabled, to still do login-less payments.