There should be no materials generated which are not needed. Could you please provide more information about which materials are generated (a screenshot or list of materials names), then we can help.
现在有一个新的中文版spine-unity 3.8到4.0升级指南，由@wiige用户慷慨提供：
There is now a new Chinese version of the spine-unity 3.8 to 4.0 Upgrade Guide available here, generously provided by user @wiige:
[ZH-CN]Spine-Unity 3.8 to 4.0升级指南
