This is actually not true, the hyper-v Free license you're talking about comes with several limitations, one of which is that it cannot legally have the management tools required to actually use the platform installed on it. Check your licensing!
Server 2016 and Hyper-V are two separate products...; there is no special Hyper-V 'free' license, it is always free. It can be managed (rudimentary level, start, stop, move, export, import) within Hyper-V Manager, a normal free application available to the Pro/Enterprise desktop OS anywhere on the network, it does not need WS2016, or System Center to manage it. Anyone can install Hyper-V as bare metal, and manage it afterwards w/ HyperV Manager remotely from elsewhere. (Some very much mistakenly think if Hyper-V 'role' as similar to VirtualBox, a Type 2 Hypervisor....which it is not...ever)
What 'licensing' are you wishing that I research? Hyper-V is free. HyperV Manager is free. System Center, of course (and all it's underlying tools, cost $1500/$3,500 extra on top of WS licensing), and WS2016 are not. HyperV can be managed with HyperV Manager, which would be isntalled on a Win8/10 Pro OS, either remotely, or locally. (Locally is what happens when the 'role' of HyperV is added.)
The fact that one can install Hyper-V from within WIn10 Pro or Server 2016 does not change that what is happening is that the original OS (WS2016 or Win10) is then actually 'scooped up' and converted into a VM, and installed as a special VM running at initial bootup of what is now actually HyperV at the bare metal layer, albeit imperceptibly.
If you are perhaps referring to System Center 2016 as the restricted 'managing tools' for running an entire datacenter, that is a separate product with other prerequisites, which of course might include a functioning WS2016 underneath...with licensing of course for WS2016 and Sytem Center.
I could run Hyper-V with no WS2008/2012/2016 VMs nearby whatsoever, however unlikely. HyperV can run an unrestricted number of Linux and FreeBSD VMs, etc... The WS2012/2016 licensing allows you to run a pair of WS2012/2016 VMs under whatever hypervisor you wish. Neither is connected to HyperV at all. I think what confuses people is that MS will allow you to install WS2016, and as long as you add no 'roles' other than HyperV, you can still run two additional WS201x VMs...
Hyper-V Manager -
https://docs.microsoft.com/en-us/wi.../hyper-v/manage/remotely-manage-hyper-v-hosts
System Center-
https://www.microsoft.com/en-us/cloud-platform/system-center-pricing