I had a BAP that registered a counter ECM and figured job done.
The event was still incomplete, so started running about with light mech with ECM set to counter (J) and did get some visible x but still no counter registered at end of match etc...
So I am guessing the counter ECM is like a reverse missile lock where the x only means you are trying to lock on but do not have the counter yet.
Only problem is if that is correct, then you could be spending a stupid amount of time trying to achieve this under 90m, and even if you do not attack opponent a) you can die or

There is no way of knowing (other than x) that you have any level of success.
Some targets might be so hard to achieve such a successful lock that it is pointless without knowing it.
Could we get something more than just x and unknown time to succeed? maybe a bar or circle like radar lock to know if there is a soft/achievable or hard/pointless target please.