How to lock the header of a list view ?

Dear all, 

I'm trying to implement new feature in Sugar 8 to lock the header of a list view. I tried to do the modification in flex-list.hbs. But it's not woking very well. I found on the community that it was possible before, maybe on Sugar 7.5 ? 

I created a case and it was classified as new feature for next time. 

Someone has already implements this kind of feature ? Do you think it's possible to implement this feature ?

Thanks in advance,

Pierre-Nicolas