IOS material sampler

When I build my project for ios platform, there is a compile error says the sampler num of a material is 17 and it exceed the limit of 16. So I want to write a plugin a detect the sampler number of the material before package. But I can only find the interface of SM5, Can anyone tell me how to detect the sampler num of a material on ios platform? Thanks a lot.

@yunmengzehaha I looked at several materials in engine attempting to locate this value. I was hoping to store it in a string and output it to screen using blueprint but I couldn’t find it anywhere.

I can get the interface of windows and android to get the sampler value, but just can’t get the interface of IOS. Is this related to the compile platform?