Thanks so much for the details! Does this method work at a single park, say you rope drop early morning Magic and hit standbys for low wait rides and us $ILL… first is there any advantage to this and second can you stack FPs like this within the same park you started? Looking for a scenario that does this if it makes sense.
Based on my experience, this would be my opinion on using Genie Plus/ILL$ for each park if you aren't hoping. Note this is based on crowd levels I experienced last week... so YMMV, depending on when you go. Also, I'm planning a trip for adults/teens, no little kids.
EPCOT - I wouldn't use Genie +. Maybe get an ILL$ for Frozen if it is a priority, or you could rope drop it. Get a BG for Remy - seems to have been pretty easy to get for most folks. You can ride Test Track in the morning or single rider if the ride is long. When we were there, Soarin rarely got over 20 minutes and everything else (Spaceship Earth, the Seas, Mission Space) were less than 10.
Magic Kingdom - You could use Early Morning Entry to ride SDMT and Space Mountain. I'd start watching the Genie Plus return times at 7 and grab one as soon as it went past 10am - PPF or Jungle Cruise would probably be a good choice for that. Then at 10, you could grab a 2nd one before you rode the first - now you have two stacked. Our experience with MK was that most of the LL were available immediately or within the next hour... I guess this could change if the park was more crowded. You could also ride things standby in the morning while it was less crowded and then use LL for re-rides, if you like to ride things multiple times.
Hollywood Studios - Grab SDD or MFSR at 7am... again, you want a time after 10am. SDD seemed to jump right to 11-12 within the first 5 minutes. Depending on your priorities, you can ride the other one of those at Early Entry or you could do ROTR. We had one morning where we were there about 8 and were able to ride SDD and TSMM both as walk ons and then MMRR with a 20 minute wait. At 10am, before using your first LL, you could probably grab TOT or RRC for the next hour. Now you have 2 stacked... but HS has less rides than MK, so you'd quickly go through all of the rides.
Animal Kingdom - I don't know if you really need Genie Plus here. There really aren't enough rides to stack. You could get there at 7am ahead of the 7:30 opening and get everything done. One morning we did AK, we rode FOP, Navi, walked the Gorilla Falls trail all by 8:45am. We then had a LL for Safari, but the standby wasn't very long (maybe 15-20 minutes). We then rode Kali as walk-on and Everest a couple times in the single rider line. I had a LL for Dinosaur at 11:15 - standby was only 25 minutes. We had ridden everything by noon. I think you could do this park in the morning with no Genie Plus and fairly short waits. If you like to re-ride things, you might be able to use LL for that... but I don't know if you could stack because the times (at least for us) weren't far enough out to get the 2 hour window.