I can't say why this feature is missing in the 436 and 536. But I had a piece of test equipment I use frequently in my job that had the an analyzer feature. First it never worked when I would try to use it and in the last firmware update the manufacturer remove the feature saying that they were told to remove it. I don't remember who they said to remove it but the feature is no longer available.
It might be best for the people that's waiting for the Analyze feature to call Uniden to get any updates each week. Maybe Call on Monday's and Thursday's.
Uniden Customer Support please call (800) 297-1023
If support doesn't know, Ask for another person higher up at Uniden,