I spoke with Matt at Lakes Region Fence, he said he could not help me, as he does not specialize in 'composite' Trex fencing. Nor could he recommend a referral.
Here is a pic of the 'cross-beam' metal brackets I have installed, which I need about 10 more of these to add 'middle' 2x4 's in each fence section. Not that it matters, but these will be used with Composite 2/4's
I've looked all-over and cannot find anything similar I could use.
Any suggestions will be greatly appreciated !