Perhaps it's worth asking a suitably qualified engineer for his/her opinion on the proximity (or not) of the crew oxygen bottle to significant electronic/electrical components . Could a problem with one cause a problem with the other?
Crew 02 bottles are on the left side of the forward EE Bay tunnel. Just forward of the EE bay/Cabin access hatch.
There are significant electrical and electronic systems adjacent to the bottles but I'm pretty sure the ATC transponder boxes are far enough away not to be compromised immediatley should a bottle fail are a fire begin in that area.