Has anyone got experience of using thickeners / rheology modifiers in beer? My concept is to find a way to increase body at lower ABV's. I know some people use Lactose, but ideally I'm looking for something flavourless.

I know that malts come with an available sugar value which you can know how much to add to achieve the desired sugar content / SG in the wort. Subtly different question - what is the typical efficiency of starch conversion in a well modified, pale malt? I have an idea which could use the...