I want to have Windows build use the higher texture resolution of 2048, while a build for Android running on a poor MALI T860 should use reduced settings.
I have a device profile made for my P9000, basically simply replacing the match rule for the MALI T8xx GPU to match my own test profile Android_Herb64_P9000 device profile.
The match rule definitely works, checking this by GetActiveDeviceProfile.
Editing Project Group 01 using the Device Profile Editor:
Setting both, Max LOD Size and LOD Bias, so that my 2048 texture, that I want to use on Windows, should appear as 128 texture on the mobile device (128 as extreme value to make change definitely visible 
)
Result in DefaultDeviceProfiles.ini:
[Android_Herb64_P9000 DeviceProfile]
DeviceType=Android
BaseProfileName=
...skip...
+TextureLODGroups=(Group=TEXTUREGROUP_Project01,LODBias=4,LODBias_Smaller=-1,LODBias_Smallest=-1,NumStreamedMips=-1,MipGenSettings=TMGS_SimpleAverage,MinLODSize=1,MaxLODSize=128,MaxLODSize_Smaller=-1,MaxLODSize_Smallest=-1,OptionalLODBias=0,OptionalMaxLODSize=4096,MinMagFilter="Aniso",MipFilter="Point",MipLoadOptions=AllMips,DuplicateNonOptionalMips=False,Downscale=1.000000,DownscaleOptions=SimpleAverage,VirtualTextureTileCountBias=0,VirtualTextureTileSizeBias=0)
LODBias and MaxLODSize are definitely in here with reduced settings.
Now assigning this Texture group to the textures in the material (leaving out normal map for now, which by default has ‘WorldNormalMap’ )
I would expect an extreme blurry texture when running on my device, but still get the high resolution.