The Option 43 hexadecimal string is assembled as a sequence of the TLV values for the Option 43 suboption: Type + Length + Value. Type is always the suboption code 0xf1. Length is the number of controller management IP addresses times 4 in hex. Value is the IP address of the controller listed sequentially in hex.
On this question, there is 1 controller with management interface IP addresses 172.16.50.5/24. The type is 0xf1. The length is 1 * 4 = 8 = 0x04. The mgmt IP addresses 172.16.50.5 translate to ac.10.32.05 (0xac103205). When the string is assembled, it yields f108c0a80a05c0a80a14. The Cisco IOS command that is added to the DHCP scope is:
option 43 hex f104ac103205

A fabric edge node provides onboarding and mobility services for wired users and devices (including fabric-enabled WLCs and APs) connected to the fabric. It is a LISP tunnel router (xTR) that also provides the anycast gateway, endpoint authentication, and assignment to overlay host pools (static or DHCP), as well as group-based policy enforcement (for traffic to fabric endpoints).
From Cisco's guide, under SDA roaming - When a client on a fabric enabled WLAN, roams from an access point to another access point on a different access-switch, it is called Inter-xTR, like a highway. Intra is within intra is between. Like interstate highways. That's how I remember. https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/config-guide/b_wl_16_10_cg/mobility.html