The only way that I can imagine that iOS can fix anything is to change how iOS asks for the bands to be checked.
At home in the country, I have a low RF signal Band 2 and a high RF signal Band 12.
But Band 2 is still faster for data.
If we have a way to cause iOS to check more intelligently for what is going on, and change bands to be appropriate for what is going on, then that might help with the problem people are reporting.
If I haven't used my iPhone in a long time, I'll pick it up and see that it's camping out on a one-bar Band 2 signal.
But as soon as I dial a number, the iPhone takes ½ a second to switch to three or four bars of Band 12.
I'm no expert, just a friendly user, and I have no idea how iOS decides all this. But I can't help wondering if the minority of users experiencing dropped calls and bad RF signal capture just need to be on a different band and somehow iOS doesn't know to switch them.
Just a wild guess from an amateur. Please don't yell at me.