I booked this morning (60 days out) and had no problems at all. I booked the hardest to get FPs first and then went back and filled in the rest. I even went back and was able to move things around, even hard ones like FOP and FEA. I think I changed 7Dwarfs about 4 times.
Yes. I did this too. I was flexible on park days -- didn't have to work around ADRs. Our challenge was this is a short trip with no park hopper. I did have a general idea of which rides we really wanted on FP.
Our trip days are Wednesday to Sunday for 2 people.
I knew we wanted FOP, so I looked for that first in the app for each day of our trip and booked it for Friday (I originally wanted Thurs - but no times available that I wanted). Then I looked for Test Track in Epcot on Saturday & Toy Story in DHS on Thursday. Then I filled in the other 2 (Tier 2) rides for each park and modified times where I could.
For MK, we're doing evening EMH &
MVMCP party.
For me it seemed like the key was to get the FP you want as quick as possible & then modify/adjust times. (Don't wait, because it seemed like they "disappear" quickly as other folks are booking there's). Once I had them set, I modified times where I could. Others may be doing the same. Times seemed to open up to modify. It was a bit tedious to shift the times one by one, it worked out fine though.
I haven't been to Disney since 2014 - i'm a novice -- totally forgot how to do the FP reservations. I read through the FP sticky on this board beforehand and it was very helpful.
I can't comment on using the computer to reserve FP. I only used the app. Hope this helps someone.