The distribution block, if it separates the front from the rear, that is fine. But if it allows mixing of the front and rear systems, that is not good; it defeats the whole reason of having a dual piston M/C.
For my car I just fished out any old Combination valve from my used parts bin, and gutted the proportioning valve out of it. The front system is still separated from the rear system by the floating safety switch.
BTW, silicone brake fluid likes to leak, far more so than regular Dot 3 or 4. With good double-flares Dot3/4 is easy to seal up. But not so with the silicone stuff; I mean I think it really likes to leak just to pizz a guy off.