Reflection texture of glass effect properties?

I read a old topic in sevenforums about Windows and Caption Buttons > Aero > Dwm Window > Reflections > Main by Bongo, and try to custom this effect. Here's one of some tests.

I notice if I use the desktop resolution image (HD for example) then the png provides sharper details on windows glass, but is so heavy (large filesize) and it make whole msstyle 4-5x bigger than original (sometimes, as I tested the HD png with complex transparency could cause Aero peek hangs windows for awhile, even in minutes). If I want smaller size, I will use smaller png but it'll make windows glass upscaled and looks bad on screen (default Aero one is good but quite hard to make the cracked glass as small and still looks well upscale/stretch).

So traditionally, I think the solution would be using a tilable/seamless texture for that image but how to set such properties in Windows and Caption Buttons > Aero > Dwm Window > Reflections > Main on W7styleBuilder? Is there such a propeties as tile in this place. Or it's unavailable?