It's easiest with micro diameter arrows in my opinion, then you still have a reasonably thick sidewall so they aren't so fragile. It's been pretty easy for me with Victory Vaps, I used their Stainless Insert/Outsert, if I build anymore, I'll use Ethics Insert/Outserts. If you are going to do it though, you have to go whole hog with it. You have to use much smaller feathers etc, if not you won't like the results in a cross wind etc. You might already have this figured out, but in my view, one of the biggest advantages of high foc is it increases the length of the lever arm the feathers act upon, that means you don't need as much feather to do the same work, but that also means cross winds don't have to be as strong to do the same work on pushing the back of the arrow around, so smaller feathers are paramount. I use 2.5 inch Shields, Ashby uses even smaller. I can usually get an arrow in the 10-11gpp to tune with them on my Toelkes.
