Copying a configuration-only client to development

for any oversights in completing transports of the configuration team. We normally do a client copy back to TST but have never done one to DEV. This would then become the "golden" client.

Yes, you can copy just configuration to development. But, never overwrite your dev/cust client. You can export Production using one of these copy profiles:
SAP_CUST, SAP_CUSV, SAP_UCSV, SAP_UCUS.
It all depends on what else besides customizing you want to copy.

I had an experience where the client wanted to start a new company and just wanted to be able to extract the customizing in the old production server into development. I exported production using SAP_UCSV and put it in a new dev/cust client. The configurators worked on the IMG to reflect the new company. Then, I copied this new client into the old dev/cust client. And this became their new dev/cust client to support the new company's production server.