Are there any recommendations for running all of part of an IBM Cloud Private cluster in a DMZ? I didn't find anything in the documentation or on stack overflow.
Please take a look on ICP Architecture.
I think if you want expose your services, you would think on the proxy part of it.
See the Architecture link: https://www.ibm.com/support/knowledgecenter/SSBS6K_3.1.2/getting_started/architecture.html