Ok, you are right, the chimes are hardly ever used on stage (expect perhaps for Christmass songs). It make it even more annoying it you miss you single chimes part just because they are not adequately positionned .
I fastened mine on a quite heavy stand that also carries other small percussions (woodblock, campana, vibraslap) and guess what, when I hit them, the chime sound bars hardly move. So the chimes cannot be accidentally heard.
So you cannot expect more from a chime holder, can you ?