You can actually do this.
After sending your invitation, on the "Share the event page"...
1. On the left side of the screen, (under "Share the event - Pending", click on the middle button: "Share event" (in between the "Confirm event" and "More" buttons).
2. Copy the "Schedule a 1-on-1" link and paste it into a private / incognito browser window, but one which is not logged in to Vyte.
3. Type the invitee's name and email address.
4. Vote as that person.