How can we improve WHMCS?

Currently you can only have one email template for when a client signs up or changes their email address. However, sending them a complete welcome message every time they change their email address is bad. It‘s just as bad as just sending a lazy message basically saying „You either signed up or changed your mail. We don‘t know lol“ isn‘t better either, especially on signup.
Since there already are two email templates for signup and email verification, why not use them both? I propose options that would let you set the template used for signups. The existing option whether email verification should be active or not should also allow setting a different template used for when a client changes their address. I also propose another variable in email templates that is true if email verification is enabled otherwise it‘s false. That way one could use the signup template regardless if email verification is turned on or not.