Option Strict and Option Infer do not conflict, so I see no harm in having both on.
As a style guide, I prefer to put Option Strict, Explicit, and Infer at the top of each class file - this prevents differences in project or IDE settings from causing issues, and makes it clear what settings are used.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…