Before using any new anchor types please do some testing. I can help and have load cells, hydraulic pullers, etc. Things do not always function as expected.
I suspect that stainless that steel split shanks do not exist and the stainless bent shanks are too weak in pull-out because the common stainless (304 or 316) are not hardenable. Maximum hardness for 316 is about Rockwell B90 which is below and off of the Rockwell C scale (Rockwell C <0).
They do work-harden a little bit but can not be heat treated to harden. Even if you do work harden them, they are very soft compared to the carbon steel split shanks and bent shanks.
There are stainless steels that can be as hard as carbon steel but they are expensive and difficult to harden - the kind of stuff that knives are made of. Making anchors out of this stuff would probably be pretty expensive. I have never met a home knife craftsman who makes knives out of stainless because the heat treating is challenging.
The only affordable stainless that is easy to heat harden that I know of is 17-4. This is what BD makes hammerheads out of. I have made some hammers with it but don't like the result because the material cannot be made hard enough. To harden it you bring it up to a certain temperature for a certain amount of time in a process known as precipitation hardening. Maximum hardness is about Rockwell C40. I like my hammers about Rockwell C50. Carbon steel button heads are probably something like C60.
