Like you in the very distant past I made a lot of these welds. I never had an issue with making the fillet full size, bringing the weld to the edge of the socket. You just have to be careful not to over heat the material. I found the biggest issue for most inspectors was the amount of expansion space at the bottom of the pipe in the socket. This space was usually defined by the design engineer or by applicable code. Lacking any definition a good rule of thumb is about an 1/8”.