My interpretation from all of the above is that as a wood it’s no better than blackwood or mopane for an instrument. For aesthetics, it shows reddish-brown early on and then darkens to “cocus brown”. And you may have difficulty finding a maker to work with it. Bottom line—if you want one, look around for someone who’s willing to work with the possible health issues (more for the maker than the player) but be prepared for changes over time.
Best wishes.
Steve
The simple answer is : No. You may not be allergic to it now, but if you get a cocobolo flute and become allergic to it over time, which can happen, you may well become allergic to all related woods, including blackwood, cocus, and all other “rosewoods”. This is not hypothetical, it happened to me (cocus was the wood that sensitized me), and now I can’t play any of the rosewood family woods without reacting, even tough I had previously played them for years with no problem. It’s really not worth the risk.
The only protection would be to spray your flute with shellac, building a couple of coats and then wax it. This will form a barrier that will probably prevent reaction to the wood, but you have to be willing to do that to a flute, or get the maker to use something besides oil on the outside of the flute.
While that would insulate your hands and face from the potential for (direct) contact dermatitis, you would, if fact, still be exposing your face, airways and lungs to potential sensitization via exposure to the allergens via the blowback airstream that comes out of the embouchure hole as you blow in. Again, the voice of experience speaking here, unfortunately. Basically, in order to avoid the potential we are talking about, one would have to have the flute completely sealed inside and out.