No problem if handled with necessary care. With HP5 permanganate rehalogenated what was developed and result was black. This was using the Foma reversal kit bleach. I'm to try if other permanganate formulas may work. I also don't like dichromate, but I feel able to use safely if necessary.
Don't hesitate to ask in the future if I can help, by PM or Flickr mail, I can delay answer a bit because sometimes I disconnect from forums...