So the evar just has the screen names and userId...We have used processing rules completely but still face the issue. uncheck the "Show unspecified" checkbox - Yes we are aware of this and use often but the requirement is to completely avoid it from implementation itself.
We have made sure that each and every hit has a value for that dimension, whether set in the beacon or persisted from previous beacons. But still we see unspecified and when we break it with custom link it shows the value ADBINTERNAL:Lifecycle
Yes, Overwrite value of (prop/evarX) with contextVariableY is how we are using.
No rules have been used in launch.
Everything done from app dev., so probably the dev will know the conditions.