At the point where I am going to install the  cross bracing to the trailing edge.
My question is the 1 /4" brace goes into the trailing edge and I assume is attached to both the spar and the gussett.
After installing the diamond gusset on the other side there is a approximate 1/8" gap between the cross bracing and the gussett.
Should there be some form of a filler block to take up the space ?
I was thinking making up a small triangular block that would be sandwiched between the gusset and the cross brace.
Or do I pull up and attach to the gusset and not worry about the gap on the other side gusset plate ?

Thank you.

The primary purpose of that ply is to tie the rib to the TE. I installed the top ones first and then flipped the wing over and installed the cross braces. They are just glued to the top gusset and TE. Then I installed the gusset on the bottom. More than enough mechanical attachment in my opinion. You’ll be shocked at how stiff the aileron gets when this is done.
Funny moment in my video of this when I realized after leaving the shop that I installed these cross braces wrong the first time.