Hello there, Robert! You sound like a fellow-expert planner, and I'm always extra delighted to welcome a keen Walt Disney World achiever here to planDisney. As a fellow U.K. resident, I know that we like to make the most of our time in the Parks.
So, as you likely already know,
Genie+ is available for purchase for each day you visit the Theme Parks (assuming you hold a Ticket and relevant
Park Pass Reservation). Your first Lightning Lane booking can be made from 7 a.m. with subsequent bookings available 120 minutes after the Park opens and every 120 minutes thereafter - or after a Lightning Lane is redeemed. In the My Disney Experience App, there is a super handy feature that shows you the exact time you may make your next Genie+ Lightning Lane booking. I like to put a reminder on my phone too, so I'm never late!
You can, of course, stack up those Lightning Lanes for later in the day. The great news is that you can now modify Lightning Lanes without cancelling your existing reservation - meaning you can try and find times that suit you best. Some of the most popular rides can book-up throughout the day, so I suggest thinking about your must-dos and selecting those reservations first. My favourite benefit of stacking Lightning Lanes is that you have more time to simply look up and enjoy the magic when in the Parks.
Robert, it sounds like you're set for a truly ride-tastic time, and I wish I was along for the thrills! I hope you and your fellow Guests have a magical time, Louise.