Thats a great explanation (though quite a bit of it was too much for me to understand).
The only correlation I can think of, is that the Kannada script keyboard and full support for the script rendering in the UI didn't exist in iOS until iOS 11.0. So it is crashing for Indic scripts that were supported pre iOS 11. Probably Apple tweaked something in iOS 11 for the languages already supported and broke something.
Thats a great explanation (though quite a bit of it was too much for me to understand).
The only correlation I can think of, is that the Kannada script keyboard and full support for the script rendering in the UI didn't exist in iOS until iOS 11.0. So it is crashing for Indic scripts that were supported pre iOS 11. Probably Apple tweaked something in iOS 11 for the languages already supported and broke something.