Zuffy,
The repad geometry of sketch 5 is different than 3 or 4, so in my opinion, no - the fillet does not provide acceptable attachment of the repad to the branch pipe.
The 328.5.4(e)(1) calls for "fully penetrated groove weld" for the repad attachment to branch pipe, followed by a fillet weld cap for sketch 3 or 4. The bevel prep on I.D. of the repad provides full thickness of repad to be joined to the branch pipe.
There is not a 'full penetration' fillet weld in my way of thinking. Maybe just one's view of combined groove/ fillet.
The 328.5.4 (f) accepts fillet welds for the outside perimeter of repad attachment of all the 3,4, and 5 options, due to the geometry of shoulder of O.D.