Hi,
Initial voucher settings don't need to be modified, ones setup correctly.
According to me, creating a new role with vouchers is a matter of clicking in the plus ( + ) button and then the blue ! button will show them all. print or save the page and that it.
I agree, all these setting called bits, keys, ticket, checksum etc look daunting.
But, hey, don't worry, you can tell you clients that "driving a car" or "piloting a plane" needs some understanding, training.
Managing a firewall like pfSense isn't exempted to this.
But: a partial solution is possible.
Knowing that voucher code are generated buy pfSense, you could store them "some where" in a file on the pfSense system.
All you have to do is adding a new tab on this page: "Status: Captive portal" where you list all created vouchers, and for each voucher you could show if it is being used, how much time is left, a "block" button to disable it, etc.
This means you could it make a easy for your client as you decide : your coding skills will determine the final result.
=> Kortom: werk aan de winkel ;)
Btw : "overall performance" is vague. many screens are can inform the admin about what's going on.