One of my family's traditions is Chef Mickey's. Say what you want about it since I know it's not the most universally (heh, last time I was there was the day I visited Universal, didn't catch that accidental pun) beloved place but we enjoy it and for us that's all that matters. Well this past time I was there, same trip as Bon Voyage Mickey skipped my table once he was done taking pictures with us and I stood there holding my autograph book without his thinking "oh wow." What makes me say this is you mentioning the handler. She came up asking if we saw everyone. We did, in the span of fifteen minutes for some strange reason that I would elaborate on if asked, told her yes but Mickey didn't sign it. She went back to Mickey and got his autograph for me. Was the weirdest character experience I ever had there. I'm only bringing this up because you mentioned the handler being more responsible there for those character. Just something I noticed in May
Again if you want to know why I had the autograph book with me at this age feel free to ask. Not ashamed I had it at all, just off topic rambling if I did explain like this.
EDIT: Ohh!! On topic I forgot when I met Olaf, the handler saw my book and told me he couldn't do autographs when I was at the front of the line, so I have seen them doing what you mentioned
I thought about that a couple times and realized, it could never work in World again. Because characters are part of the integral "experience" for families unlike daytrippers and every other group, it's best to have them in a set area after all. Another reason is crowd control. Think about it, if Anna and Elsa freely roamed the Magic Kingdom, how congested would that area become? As much as I like the idea of free-roaming characters, I just don't think it can work in World.
Lastly, I'm an adult who still enjoys meeting characters, is that bad? Some posts make it seem like it is