I wonder if that is what I was running into as other than one rotating through all of the definition files the other flipping between the two, they seemed about the same (just jumped to the file, but not to the associated parameter definition).
^+` would flip between c/h files, but not even to the correct function (let alone parameter). Alt+` would cycle through all the files, land on the beginning of line of correct line of the function, but not to the corresponding parameter. When it cycled back to the original file, the cursor location was reset to beginning of line.