This doesn't work for trinkets that don't need buff stacks to be activated, so these stacks are probably the reason why it works with this trinket and the tinker. For engineers this could even increase the value of FoA cause you can pop trinket and tinker together with another CD.
Just macro both making sure you use your tinker First, then FoA. Will not work if you macro FoA + tinker, must be tinker first, then FoA.
Enjoy while it lasts as it'll probably be getting hotfixed soon.
Ideally, the macro should look something like this:
Code:
#showtooltip whatever you want
/use 10
/use Fury of Angerforge
/cast *insert cd here*
/script UIErrorsFrame:Clear()