If I am reading your guidance correctly;
The decision for when or if to use a 2H, is driven by how far up the Gelid Rending AA tree the BST has climbed, raidloot details here.
lvl 105, Rending 6, gives claw rank 4.
lvl 110, can go to Rending 10, which gives claw rank 7.
lvl 115, it's to...