After a little search on lasers in this forum, I realise that most are used for cutting wood.
My hope is to ‘attach’ a laser to my Nomad Pro for etching (not cutting) metals like brass, silver, gold. Is this a pipe dream or is it possible? From the little I read, it seems fiber lasers (vs diode) are needed for metal engraving?
Your research is correct. Some diode laser sellers market the ability to engrave Stainless, and it sorta works, but no where near as good as a fiber or MOPA.
Most users of lasers are attaching them to the Shapeoko. The Shapeoko has a larger cutting area over the Nomad. So attaching a laser to any machine will alter its cutting area by the offset of the laser module. With the Nomad cutting area relatively small you will be limiting your lasering area. For jewelry that might not be a problem. I do not remember ever seeing anyone on the forum utting a laser on their Nomad. That does not mean someone has not done it but if they do it is rare.
I might be more advantage to upgrade to a larger machine and add a laser or simply buy a dedicated laser machine.
I am sure if you search hard enough there might be a kit for your type of laser made for the Nomad. Unless you are going to do a lot of this type of work it might be better to find a local person to do your laser work. Good Luck