Hey there, Greg!
Thanks for bringing your question to us today. I'm all about maximizing my time in the parks so I'm happy to help!
Yes, you can purchase
Lightning Lane Multi Pass or Single Pass for a different park than your starting park with eligible
Park Hopper Option tickets. Once you are within your booking window (7 days before check-in for eligible resort guests and 3 days before ticket start date for off-site guests) you can purchase and begin making your selections. Your strategy in this example is a great one as
Disney's Animal Kingdom Theme Park often opens earlier than other destinations. You should have no issue "rope dropping" your favorite attractions via the standby line there and then making your way to Magic Kingdom Park for the rest of the day.
Keep in mind that
park-to-park buses typically begin running around 10 a.m. each day. If you will be utilizing complimentary transportation between the parks you'll just need to plan your Multi Pass arrival windows with travel time in mind. I'd recommend planning at least one return window at
Magic Kingdom Park as early as you can get there so you'll be able to make additional selections, subject to availability, once you've redeemed one of your initial three selections.
I'd also like to mention that
TRON Lightcycle / Run Presented by Enterprise recently became available via standby instead of a Virtual Queue. However, the attraction is still available to experience by purchasing a Lightning Lane Single Pass. which I find helpful especially if you want to ride at a certain time of day (nighttime is pretty awesome, in my opinion).
Tiana's Bayou Adventure is available as a Multi Pass selection or via Virtual Queue, at this time. I rode for the first time a few weeks ago and loved every soaking wet moment!
I hope this helped clear up any confusion, Greg. If you have additional questions please don't hesitate to come back and let us know.
Magic and memories,
Amy