Email-entered-twice function
These days many forms request you enter your email address, and again for clarification.
Such a feature in Machform will be very handy. I am thinking it could be accomplished if the Conditional Logic feature had additional logic rules such as to compare the value of one field to another - I can't currently see such a thing in V5.0.
So the idea is that a rule is defined but using the logic operator "not equal to" ( <>). So that you compare "email1" with "email2" and if they don't match, you get the usual red-text error (but should be able to customise the message).
It would mean adding a new Conditional Logic section for "Field Comparison".
Other way to do this would be to add the functionality to the field properties for email field; such as showing the second field for the email data entry, and having a standard behind-the-scenes logic check of the data and also incorporating a customised message (something like you can now do for offline forms etc).