This may have been a change in FMGo that was done to address other issues. You may try having a frozen "loading" layout for a static amount of time or maybe calculated on a response time from a PSOS script.
Is you layout too heavy? Try lightening it up If possible.
I have some JPEG heavy layouts and to get them working well on iOS with a decent image I use a thumbnail that is 1.5x the container size but run the JPEG compression quality down to 40 or so for the thumbnail. This generally results in a smaller file size that loads faster but still is visually nice for the user. Keeping the original large images in a separate table also helps a lot.
I have some some list view layouts with thousands of images and they load pretty quickly even over slow WAN. Never wait more than 5-10 seconds for 1000 images at the slowest.
Properly using styles helps too.
Just saw the ref. doc note. Not sure about that.