@Clive_A I understand that a true release of a DHCP lease is done on the client level. Most of the time I don't have the capability to access all of the computers or devices that are taking up the current IP address leases. I would like a way to release the entry from the router, so I can bind IPs to mac addresses, or just free them up in general. This also comes into play when you have a limited scope DHCP pool.
Say you have hundreds of routers with VPN and you only assign them a /28 range. The remote office has enough equipment to fill most of that range with just enough to spare. However, a surge in staff one day means some cell phones were connecting to the network, and now there's not enough IP addresses to go around. I would like to release those phones from the DHCP pool on the router, not block them.
Fortinet has Fortimanager cloud management for their Fortigates. There is a feature called DHCP Query. From there I can see the connected clients and release their lease.
Ubiqity cloud management has a feature to "reconnect" clients (it's also on the phone app).
I'm sure there's more out there, but this is what I can dig up on a moments notice. We can argue semantics about how this process really works, but I would like a smoother, more intuitive way to accomplish this goal, instead of the current "Block" feature.