Hi Again Morten,
Let me try to summarize what works and what does not.
Xamarin.Forms.Android (Android API 17, 4.2.2 with custom/esri.github xamarin sample)---Crashes
Xamarin.Forms.Android (Android API 23, with custom/esri.github xamarin sample)---Works
Xamarin.Android (Android API 17, 4.2.2 with custom/esri.github xamarin sample)---Crashes
Xamarin.Android (Android API 23, with custom/esri.github xamarin sample)---Works
We already have an app created using xamarin forms and works nicely on android and ios, except for the above mentioned leica device, just for fun i tried installing the collector app in the leica device and works like a charm. So now, i am not sure what could be going wrong here....
Would prefer, if you could try out a simple test using the 4.2 SDK and if it works do send me the code, then i can drill further.
Regarding your suggestion on the faster loading & UI, we have already done quite a lot of work on the forms and is relatively stable on the both the platforms.
For the mapping part we have a single instance of the mapview with snapshot of the operational layers.....once this is loaded for the first time, this object gets attached/detached in different layouts..which considerably reduces the load time on each pages.