Yea, if you just have the brain light up a LED when the limit LED is on, then, you have the same problem, you need a way to latch it.
If it is possible to have the brain write to a DRO depending on the status of the LED, then it would behave the same way, it would change to 1 when on, and 0 when off.
What you can do is have the Brain look at the Limit LED, have that LED activate a timer that will start right away, and set the pulse duration to something big, like 120, and have that timer turn on a usedLED, one for each limit.
That way when the limit is triggered, the timer starts counting down for 120 seconds, and while the timer is active, the UserLED will keep lit.
Then you have to make sure you can get to the diagnostics page in less than 120 seconds to see which one was triggered.
Fernando