Implemented changes to Shield Skin and Greater Two weapon Defense feats as discussed in this thread: viewtopic.php?f=5&t=4916&start=10
Amend GTWD = BAB/4 (max.10).
Amend Shield Skin = (BAB /4) + 1 IF STR > 30, OR + 2 IF STR > 40 (max.12). Give double weapons access to Shield Skin but with a -4 penalty for DW use (max.8).
Commited to Git. Erroneously stated the commit was for "Shield AC Under review" Forum topic, sorry for the confusion.