If he doesn't have dysgraphia having a scribe for now doesn't mean it will always have to be that way and that by allowing for it will mean he will necessarily be dependent forever.
DS was diagnosed with a processing speed LD and his IEP allows for scribing. When all of this happened last year I admit I was hesitant because I was worried we were giving up on writing too easily. However the frustration that he was experiencing was making him hate school which also wasn't something I wanted to set up for life either so I listened to the experts and we scribed most of his homework (which was pretty much all of the work he was supposed to do during the day but didn't). We scribed a lot last year but this year it has been happening less and less. He is still has messy writing and is slow but it holding him back as much as it used to and more importantly it has allowed him to relax. Scribing seemed to remove some of the pressure and then he was more willing to try to do some of it which allowed him to improve. Every kid is different but I just wanted to throw it out there that maybe what seems like less practice is better in some cases since it keeps the door open a bit. He was more willing to do it when he knew it was going to be short and then we were able to do it more often which in the end added up.
Not sure if my rambling made much sense but I just wanted to address your fear since I felt the same way. Hopefully you can find something that works for your situation.
