Depends on how old the kids are and what rides you'll want to do. I could see it being helpful as you could theoretically find 2 or 3 ride times available in the late afternoon to early evening that you can stack for your return to the park. Especially if you wanted to grab jungle cruise, Peter pan around noon and 2. But if you're only doing the rides that are always under 20 minute waits, probably not useful.
Today actually seems like a day you could use as a planning template. You could plan to grab one or two easy to use passes in the morning like pirates, haunted mansion, buzz, etc while also going on the fun kids rides with little waits. At noon ET, check jungle cruise and at 2 check Peter pan. If those are rides you want to do and the times available fall within a time you think would work on your day, I'd say the genie would be worth it.
