If you use them together you need to make sure both sets of beads are at the same RH. No problems otherwise.
Having said that -- if you have HF Beads and you are happy with them then I would stick with them. HF and HCM beads are maintained very differently and it could be a source of confusion down the road when you accidentally add some water or spritz the HCM beads...
If you are unhappy with the HF beads I would like to know why you want to switch -- sometimes switching beads will not solve your problem. It's not that I don't want your business, but I would rather have a happy BOTL and a happy customer even more.
RC
; otherwise Coke.