fenix 5X memory limit

I have developed a widget for my fenix 5x which works flawlessly in the simulator. It has a large data set and I knew it would never run in the fenix 3 so I created a cut down version to test on the fenix 3 while I waited for my 5x to arrive.

So, my fenix 5x arrived today and I excitedly side-loaded the widget but it crashes on startup with out of memory errors. So, I side-loaded the cut down version which works on the fenix 3 and this crashes with out of memory errors when I try to move of the main view to the next view.

So, it seems that even though devices.xml and therefore the simulator implies the 5x had much more memory available, this does not seem to be the case. Can someone at Garmin comment on whether the fenix 5x really has extra memory available?

When using the cut down version in the f5x simulator, when the widget starts on the initial view it shows memory usage of 57.0/1018kB, moving to the next view the memory usage increases to 90.7/1018kB. So in both cases, way below the limit shown.

When using the same cut down version in the f3 simulator, when the widget starts on the initial view it shows memory usage of 41.1/64kB, moving to the next view the memory usage increases to 59.0/64kB. In both cases here, below the 64kB limit. I guess the memory used is lower than on the f5x due to it being CIQ 1.x rather than 2.x.

So, it would appear as if the real 5x has a 64kB limit and not 1018kB as shown in the simulator. This would explain why the full version does not work at all, and the cut down version crashes when trying to move to the next view which pushes the memory usage above 64kB.

Can anyone from Garmin comment?