Dear Steve
Thanks again for your question.
Unfortunately I did not actually answer you completely.
A language act could address the lack of implementation of language rights simply because it could do more than a mere declaration of officiality can do, especially given the relative weakness of South Africa's language clause. The Dutch Sign Language Act is a good example of exactly this - it really spells out detail about what has to happen regarding this language where and when.
Also, a language act can reconcile the variety of provisions regarding SASL and the Deaf that we find in various pieces of legislation, as I argue in my written presentation. This will hopefully help officials to better implement existing legislation to the advantage of the Deaf community.
Best wishes
Theo