When events are billed as 24 hours rather than a distance they tend to be lapped arrangements where you do as many laps as you can in the time but can take breaks for food, rest, first aid, etc, between laps. That can significantly separate the average pace metrics for "overall" and "just moving time".

Events like Equinox24, Endure24, and a few others in the UK (I'm sure other places have similar events too), for example, have 5 or 6 Mike laps over varied (but usually not technical) terrain. There are people who just walk these events too, the events tend to be quite open and welcoming to different styles and abilities, sometimes managing more than 50 miles. It can be surprising how much "time on feet" can matter more than pace after a few hours. I start running but by the end the best I can manage is a zombie shuffle, which is slower overall than normal walking pace.

Only about 1800ft total elevation, which isn't much when you average it down and take into account a couple of hours here and there to swap plasters, eat some scoff etc.