What does the member "AlphaMode" do when creating a DXGI swapchain for Direct2D device contexts?

Question

I am currently creating a game using Direct2D. For rendering, I want to use D2D's device context because it allows for more control and effects etc. I have created the HWND swapchain as usual and it works. I have already tried Alpha Blending using semi-transparent rectangles partly overlapping, and it seems to work. However, when I create the swapchain, I specify DXGI_ALPHA_MODE_UNSPECIFIED as its AlphaMode, but D2D1_ALPHA_MODE_PREMULTIPLIED when creating the Direct2D render-target (a bitmap in this case). Changing DXGI's alpha mode does not seem to change anything apart from failing the function when specifying DXGI_ALPHA_MODE_PREMULTILPLIED.

What does the AlphaMode of DXGI do when using a DXGI swapchain for Direct2D (and only Direct2D) rendering? Can I expect it to work without problems even though the AlphaModes for DXGI and D2D are not exactly the same?

As I said, it does work so far. But I am afraid it may introduce problems later as I get into more complex things such as per-pixel alpha bitmaps, and effects.

Here are the structs used to initialize the swapchain and D2D's device context (some, for this question, irrelevant code has been omitted):

    static D3D_FEATURE_LEVEL const eaD3DFeatureLevels[] = {
        D3D_FEATURE_LEVEL_11_1,
        D3D_FEATURE_LEVEL_11_0,
        D3D_FEATURE_LEVEL_10_1,
        D3D_FEATURE_LEVEL_10_0
    };
    DXGI_SWAP_CHAIN_DESC1 sDXGISwapChainDesc = {
        .AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED,
        .Width = 0,
        .Height = 0,
        .Flags = 0,
        .BufferCount = 2,
        .BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT,
        .Format = DXGI_FORMAT_B8G8R8A8_UNORM,
        .Scaling = DXGI_SCALING_STRETCH,
        .Stereo = FALSE,
        .SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL,
        .SampleDesc = {
            .Count   = 1,
            .Quality = 0
        }
    };
    D2D1_BITMAP_PROPERTIES1 sD2DBitmapProps = {
        .bitmapOptions = D2D1_BITMAP_OPTIONS_TARGET | D2D1_BITMAP_OPTIONS_CANNOT_DRAW,
        .pixelFormat   = {
            .format    = DXGI_FORMAT_B8G8R8A8_UNORM,
            .alphaMode = D2D1_ALPHA_MODE_PREMULTIPLIED
        }
    };

[...]

gl_sApplication.sRenderer->sD2DRenderer.sDXGIFactory->lpVtbl->CreateSwapChainForHwnd(
            gl_sApplication.sRenderer->sD2DRenderer.sDXGIFactory, 
            (IUnknown *)gl_sApplication.sRenderer->sD2DRenderer.sD3D11Device, 
            hwRenderWindow, 
            &sDXGISwapChainDesc,
            NULL, 
            NULL, 
            &gl_sApplication.sRenderer->sD2DRenderer.sDXGISwapchain
        );
    D2DWr_DeviceContext_CreateBitmapFromDxgiSurface( /* wrapper function to expose Direct2D's C++ interface to C */
            gl_sApplication.sRenderer->sD2DRenderer.sD2DDevContext, 
            gl_sApplication.sRenderer->sD2DRenderer.sDXGIBackbuffer, 
            &sD2DBitmapProps, 
            &gl_sApplication.sRenderer->sD2DRenderer.sBitmap
        );