I've noticed that during the charge down process, they abruptly stop tracking their targets. This has been around for a long time, but I couldn't figure out what it was at first (I thought it was something in the modded weapons I was testing, where it was more obvious due to their longer cooldown time) - but then I more recently observed (and noticed it long enough to remember, instead of forgetting in the heat of the battle >.<) it happening quite evidently with vanilla weapons (specifically I noticed it with tac lasers)