Best coating for rim dies

We are currently manufacturing rim type tooling. We are struggling with the best coating several of the Resin manufactures say chrome is best several say nickel.
These dies are low flow so wear is not a factor. the tool will have inmold coating put on the cavity side before it closes. We are trying to get rid of release agents.

I personally would rate nickel very high only if composed with Teflon or Molly disulfide particles, but plain electro or electroless nickel would be inferior to chrome given the same thickness. Other very popular and successful options are PVD Titanium or Chromium Nitride coats. More exotic and expensive but perhaps even better would be other nitrides or intermetallic compounds. These are all very slippery and thin but very hard and high temperature resistant materials.