Normally, one can label hostiles spotted by sensors to learn their class and, possibly, rating. However, that same thing does not happen when using FC or RIF ability.
Obviously one can see the class of a robot from the tile picture or ascii character that represents it. Furthermore, it seems that tier of the robot is also visible with those methods via coloring.
As later discussed on Discord, this wasn't a bug but just a feature that didn't exist yet because at the time I couldn't find a good way to merge it with the original sensor system (these mass labels have never been available for FC/RIF, only individual labels), but I've found a way to add it for Beta 9.1, so it'll be in there shortly!