How to specify a fixed mode for BC7 encoding?

Hi, I'm sorry to post this question here. It is a question rather than an issue.

I'm trying to fix the output mode of BC7 encoding. However, the documentation about the BC7_enc_setting is not sufficient for me to find out the answer?

Let's say, if I want BC7 encoder to always output mode1 compressed block, is there a way to do that?

Thanks a lot!