I'm storing vertex attributes in a buffer exposed through a Shader Resource View.
In my vertex shader I'm declaring "Buffer<float4> in_pos_buffer : register(t0);" and then load it using SV_VertexID.
In some case I'm using D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_0 and D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_1 to save some write.
According to users with a Radeon card however it doesn't work and the gpu is still fetching the data and thus glitches does appear since the data is left uninitialised.
However it looks like it should be a supported scenario since Microsoft Basic Renderer is correctly rendering the vertexes in the same situation.