When I make a simple hole in a sheet metal part, it's much easier to sketch and dimension a circle then use the sheet metal "cut" tool to create a hole. Much easier than using the "hole" tool or the "punch" tool. Unfortuantely there isn't a sheet metal "cut" option in the "Automatic centerlines" tool so holes created in this method do NOT get automatic center marks. It seems like it would be an easy upgrade to have the "automatic centerlines" tool also include sheet metal cuts that were created from circles.