If you use a good quality zip tie I wouldn't worry about it. Probably last longer than the regulator. LOL
I have to wonder if there is some movement on the cable in that area if it might wear on a stainless one possibly eventually breaking/cutting it.
In this instance I think the nylon zip tie might be the better choice. TBH, I've never had any regulator problems though.....so far.....all I'm going by is from looking at pics.