I have some other small machines (which are running ME 12). Would it be possible to upgrade to 16 or are they chip specific.
No, ME version are Intel platform/generation specific.
Info and guidance are present in the forum…
Intel (Converged Security) Management Engine: Drivers, Firmware and Tools (2-15) - Special Topics / Intel Management Engine - Win-Raid Forum (level1techs.com)
Thank you for clarifying.