How can I set a contact's last name from Wix Bookings?

I’ve noticed that the wix-bookings collects a single name field (rather than discrete first and last names) and on a successful booking, the name field is transposed to the first name field of the contact in the contact list. I’d like to collect separate first and last names, as a Wix Form would.

I’ve tried adding a custom field called to my booking form, and thus to the Form Fields objects for each item in my Bookings/Service collection:

{ "fields": [
    {
      "_id": "00000000-0000-0000-0000-000000000002",
      "type": "email",
      "label": "Email",
      "link": null,
      "constraints": {
        "required": true
      }
    },
    {
      "_id": "00000000-0000-0000-0000-000000000003",
      "type": "tel",
      "label": "Phone Number",
      "link": null,
      "constraints": {
        "required": true
      }
    },
    {
      "_id": "00000000-0000-0000-0000-000000000001",
      "type": "text",
      "label": "First Name",
      "link": null,
      "constraints": {
        "required": true
      }
    },
    {
      "_id": "8b74779c-32ef-4467-aac5-eb5c5ff46be7",
      "type": "text",
      "label": "Last Name",
      "link": null,
      "constraints": {
        "required": true
      }
    }
  ]
}

My checkoutBooking code:

$w('#submitButton').onClick(async () => {

 const firstName = $w('#firstNameInput').value
 const lastName = $w('#lastNameInput').value
 const email = $w('#emailInput').value;
 const phone = $w('#phoneInput').value;

 const formFields = [{
 "_id": "00000000-0000-0000-0000-000000000001",
 "value": firstName
                        },
                        {
 "_id": "8b74779c-32ef-4467-aac5-eb5c5ff46be7",
 "value": lastName
                        },
                        {
 "_id": "00000000-0000-0000-0000-000000000002",
 "value": email
                        },
                        {
 "_id": "00000000-0000-0000-0000-000000000003",
 "value": phone
                        },
                    ];

 const bookingInfo = {
 "slot": selectedSlot[0],
 "formFields": formFields
                    };

 await wixBookings.checkoutBooking(bookingInfo)
                        .then((results) => {
                            $w('#bookingStatebox').changeState("state4");
                            console.log("bookingId", results.bookingId);
                        })
                        .catch(err => console.log("checkoutBooking error", err));
                });

On a successful booking, the contact is still created with a first name only. The last name defined here isn’t anywhere on the contact, not even as a custom field.

How might I go about adding the last name to a contact, and why the discrepancy between a typical Wix Form (first name and last name) and Wix Bookings (name only)?

I’ve considered using wix-crm createContact to manually update the new contact with the last name input’s value, but I’m hoping there’s a more elegant way…

Thanks in advance.

Edit: my custom Last Name form field does populate under the respective contact’s booking info (as below) but no where else.

Edit: @Yisrael (Wix) might you be able to shed some light on this please? I’d be keen for someone to address this, even if it is relatively minor. I have reverted to collecting a user’s full name in name form field (00000000-0000-0000-0000-000000000001) by concatenating firstName and lastName for now, so contacts are created with their full name in the first name field.