I've had great luck firing low fire reds at 07 separately form other pieces. I've fired the low fire glazes first, then had students put on the red they wanted--we have several.
I reload the kiln and fire at 07 with a kiln sitter on at about 4 hours. The peep holes are all open and the lid open for the first 2 hours. then I close the lid and all comes out a great wonderful red. I've also been doing the oranges this way for years with great success.