I recommend the following:
- If you're hopping to Epcot for the evening and want to ride Soarin' or Test Track (or if you're hopping to HS and want to ride TSMM, RnR or ToT), you'll have to pre-reserve your FP+ in Epcot (or HS) for that day, because otherwise they'll be gone by the time you hop there in the afternoon. Having FP+ pre-set for the other parks is less important -- MK has much higher FP+ "inventory" and will typically still have some good ones left in the latter half of the day, and at AK, the last hour or two before closing will generally have low crowds, making FP+ less necessary.
- For your morning ("hop from") park, arrive at rope drop and hit the biggest headliners right away. Just as in the old days, if you know which attractions to prioritize, you won't need to you any FP+ at all to have consistently short lines in the first 2 hours after rope drop, even with a regular park opening (no EMH). For that reason, I wouldn't schedule any FP+ earlier than 10:30 or 11:00am because they'll be unnecessary during that time, unless you just need to "burn" some of your FP+ in order to make yourself eligible to book a 4th FP+ at your afternoon ("hop to") park. (*Note: FP+ has made some subtle changes to "which attractions to prioritize" -- most notably, Dinosaur, POTC, Little Mermaid in MK and Haunted Mansion have all doubled their average wait times with FP+, so you'll want to do them earlier in the day than perhaps you used to. That's about it, though.)
During my family's visit in May, we typically took advantage of rope drop arrivals in the morning and scheduled all of our FP+ for the late afternoon/early evening hours. We did all the headliners and rarely waited more than 10 minutes for anything all week.
Don't sweat it -- have a great time!