In mobile services contextData is passed in a Key/Value pair, it seems rather "old-school" to then require an admin user to go in and remap the key again to a different system level key. Understandably this is done to provide cross compatibility with SC/Adobe Analytics, but by default you could have a contextData key to Friendly Name mapping for AMS and Workspace, and then optionally use props/evars for components that would need to be used in SC. If a contextData key is not mapped to a Friendly Name then it is not processed otherwise the import processing just needs to locate the contextData key rather than an additional mapping.
This would remove the limits on props and evars, and lighten the implementation effort.
Thanks.
-Lee