For me when the string starts to twist, I would pull it through the grommet first, when I get to the end hold it so you pull the twisted part through and the rest might have a slight twist maybe a half a twist or a full, not wound up like most stringers might think.
Yes sure, you can do some "tricks" to work with twisting strings to avoid having the twisted parts not inside the stringbed. But this is not optimal for me. As someone who also strings tennis, you should also know natural gut. Imagine doing the same with natural gut. You can do as much as you like, if the string starts twisting it will turn the outer layer loose. Yes, badminton strings are not that fragile, but I can't imagine that it's good for the string.
And please tell me at least one disadvantage of the awl, except that it's like pineapple on pizza. Yes, you can damage the string with it, if you're using it wrong. But you can do a lot wrong while stringing. And the awl is on of the smallest problems.
I now string a few rackets a month and if the customers string break quickly, I usually ask my customers where it broke. I have never heard of a string breaking at the shared holes.
It sounded like you mentioned having to use the awl at one point. But that was your last resort. To me it sounds like some of these people are going the easy route and just trying ti use the awl as the first thing to open the grommet without trying. I am ok with new stringers going to the awl, not a fan of it, but it shouldn't be your go-to tool when you get to the shared holes.
No, I had already tried using the awl before. The awl was difficult to get through. The string didn't go through at all, regardless of the angle. Then I tried again with the awl, but a little further than usual. Then the string broke. So I suspect that the grommet was already damaged (on the inside) before. The grommet had already been twisted several times and looked like a flower.
Since two month I'm using the awl on the bottom too. Before that, I actually only used them at the top (with a few exceptions). Before I start with the crosses, I put my awl in the shared blocked holes on the bottom and when I get to the top I do the same with the shared blocked grommets there. Then you know exactly (with a few exceptions) in which angle you have to put the string in or where it comes out (top or down).
Everyone has their own style (art) of stringing. I usually respect many and think it's great that there are so many styles. You can always learn something new.
I also respect it when someone uses the hook, but I still don't like it

For me it's not optimal to use the hook, but it's not wrong either.