This has now been implemented in Beta 0.35 :)

Multiply your specular ambient by your specular AO map

There should be, I'm doing a cleanup pass for the whole flow of the shader compiler. It will take a week or two though

Are you getting any errors in any console related to the shaders?
What is the common feature among the shaders that work?
What is the common feature among the shaders that don't work?

No idea what could be wrong. Try it with super cheap shaders (Color into emission), and see if there are errors in any log somewhere

Ah, alright! Closing this then :)

Thanks a bunch for the descriptive screenshots :)

Looks like I'll have to set up an entire lab to test all of the cases for this, I'll look into it now

It could also be that you're missing a Color property named Color, multiplied by the diffuse texture. Although it does look a bit fishy. So the shader is set to forward rendering - what render path are you using on the project/camera?