Firstly we used recommended software version for S5700 --- V200R003C00SPC300.
This version suggests mac-bypass function. But if we made authentication by mac, and after it 802.1x become available process of re-authentication will begin. It was not suitable for customer.
From Huawei product documentation

Comparing with Cxx manufacturer switches: Cxx manufacturer may act as both Case 1 and Case 2. Huawei can act only like Case 2, when using V200R003C00SPC300 version.

We tested S5700-52P-PWR-LI-AC. At V200R006C00SPC500 release we can config like Case 1. Following commands appear. Unified Mode has been realesed.
[interface view] authentication mac-authen dot1x
authentication single-access
At V200R007C00SPC500 version command authentication device-type voice authorize appeared. It helps not to use authentication for VoIP phones at all.
So for desired auth scheme we advised customer to use V200R007C00SPC500 with Unified Mode NAC.