find him a string that feels good to him and teach him to straighten his strings if need be??
I've been straightening strings all my tennis years, what's the big deal?
....and i know about poly snapping back, yada yada. i play cheap string (syngut mostly) that i straighten as needed. guess i'm gettin' old....
sounds kinda anal to me, but maybe a soft poly of some sort??
otherwise, continue the whizzing. carry on!