For the guys that noted a slight performance decrease from 3.9 to 3.10. We did some profiling and tracked it to the change in HDR format handling.
In 3.9, we had a thinner HDR buffer, RGB10A2, which has lower cost to fill out for the HDR postFX compared to the fatter RGBA16F buffer in use for 3.10 at the moment. The reason for the shift is that, with the linearized lighting introduced in 3.9, with HDR enabled you could get color banding, as the RGB10A2 texture didn't have the bit depth necessary for smooth colors in some lighting situations, specifically dark ones.
So for 3.10, in the interests of more accurate colors/reduction in banding, we upped to the fatter buffer texture. This unfortunately means that HDR has a slightly higher cost.
Post-3.10, we're dropping Dx9, and switching over to sRGB and a much leaner gbuffer(timmy's already got this all sorted, we just need to drop it in, basically), as well as some improvements to the HDR effect. All that together sees far, far more accurate color handling, with a performance increase as well.
For 3.10 though, if you're willing to deal with a bit of possible color banding in darker areas, you can roll back the fatter HDR buffer tweak and that should get the perfromance back to where 3.9 was by uncommenting this line:https://github.com/GarageGames/Torque3D/blob/57dfeb829a40fb88c974d9370d70e8dcadeb650b/Engine/source/gfx/gfxDevice.cpp#L1324
That'll make the HDR format default to the RGB10A2, which as said above is lighter and thus costs less to utilize HDR, but at the expense of less accurate lighting and possible color banding.
for #1746, I have a PR pending I just need to make a tweak to tonight and will get rolled in. Plan is to get fixes for a few more issues that people ran into and have an RC2 pushed out this weekend.