Using Appointment Slot Widget in Form, but would like to allow multiple guests to register for appointment...

Been building this form for a while now; its for an event registration - I have limits set up that only allow for the form to be submitted once by the same email address/cookies & IP... Problem i'm facing is complex:

We offer multiple days for the event, but users can only register for one event all summer. After some recommendations, I went with the Appointment Slot Widget so that I can cap each event at the capacity limit for the lesson (8 people per lesson.) However, I'm trying to figure out a way to allow the person registering to add multiple guests (ie: parents sign up themselves and their 2 kids, totaling 4 people for a lesson.) I'm trying to figure out a conditional formatting that will allow them to add attendees, while still only being able to select one date from the Appointment Slot Widget, with the widget recognizing that 4 people are being signed up for that date, so only 4 remaining spots are available.

(Sub Question...) Also wondering if under the Form Settings > Unique Question if there is a way to select more than just Email (I'd like to limit submissions based on Guest 1 Email, Guest 2 Email, and Guest 3 Email along with the main email of the person submitting the form.)

I hope this makes sense. The URL for the form is below for reference.

Flow of the form I'd like to achieve: 

User enters name, email, phone, then selects if they are bringing guests (No, Yes +1, Yes +2, Yes +3) they enter in each name, email, and phone for each guest. They then select the lesson they want based on the date and the remaining available spots (capped at 8 per lesson.) When they select that lesson, conditional formatting will register that this user and their x number of guests are registering for that lesson and once they submit the form, the Appoint Slot Widget will deduct how ever many guests register on that form from the remaining availability (ie: I register myself and 2 guests, 3 people total, hit submit, then the availability for that Appointment Slot goes from 8 available to 5 available.)

To allow multiple registrations you will need to replace the widget you're currently using with the Quantity Gift Registry widget, here is the link: https://widgets.jotform.com/widget/quantity_gift_registry 

This guide will help you adding the widget to your form: https://www.jotform.com/help/252-How-to-Add-a-Widget-to-Your-Form 

Now, as you have noticed on the unique question you cannot select more than one field, but as a workaround, you may add a new field to your form and copy the value from the fields you want to set as unique question, then select this field on the form settings. 

To pass data from one field to another you may follow this guide: https://www.jotform.com/help/286-How-to-Pass-Field-Value-to-Another-Field 

I hope this helps.