The hardware will still be sitting on the threads of the Trek bolt which just doesn't sit well with me. Even though there isn't much rotation as you said, wear is an issue as the threads will eat at the aluminum over time ... which then you'd have to buy the same replacement and end up being the...
What would a smaller DU bush solve when its actually due to a gap between the mounting hardware and the bolt?
Do you mean mounting hardware? They are considered consumables as they wear over time (especially if its rotating on threads).
Is custom mounting hardware really considered an optimal...
Usually thats the quality of materials used and finished, rather than dimensions ... but please do check! Would be a good alternative if theirs is 7.99 off the shelf
All shock hardware which is mass produced are ~7.99mm.
All off the shelf general purpose M8 bolts are ~7.85mm.
The usage of bolts as pivots for bikes makes up like probably 0.001% of worldwide bolt usage.
I think if shock manufacturers made shock bolts then it would potentially limit frame...
I posted this on the Trek Fuel EXE owners group on FB but thought you guys might find it useful too.
Some of the information has already been mentioned by members here, but I've just collated it and put some more insight into it from my findings...
Can you provide a photo of the head out of curiosity? Just talking to some guys that can do this job but a visual of how much gap between hex thread and edge of bolt would help.
Also a measurement of the bolt head diameter would be great too. It should be around 12.8-13mm