metallic threads are not made to be used in 'high-speed' machines- it stretches and breaks from the speed of the machine-
some long-armer's have spent hours and hours working with them and found ways around the problems- and you usually pay for that- using metallic thread for your quilting can double the quilting charge.--they increase the time/work requirements ALOT.
if you really want metallic (highlights) on the top of your quilt maybe you could add (embellish) after the quilt is quilted.
if you do not mind paying (alot more) there are quilters out there who can accomplish what you want- although rayon or silk threads that have a fabulous sheen may be a better alternative