Even though this thread is meant to be about internal rules, it may be useful to keep in mind existing external rules that constrain events. By definition, our events will not place on a closed circuit, but on public land and it will be wise to set them up in a way (including the terms) so that they don't become outright illegal. That actually is a different link back to the randonneuring idea (which I really consider the spiritual ancestor of our bikepacking events: extremely long distances, self-supported, with time limits, but the main idea that you challenge yourself while trying to beat others may be somewhat secondary).
Some of the fundamental issues come down what is a race and what isn't. That very topic kept French lawyers (and courts) busy for years in the context of "randonneuring" In that case, it had to do with government subsidies, so randonneuring were the "non-race races". If you look at them, they look (or at least used to look, things have changed) an awful lot like bikepack racing, only distinction being that they are primarily on paved roads (with a bit of gravel or dirt at times) and drafting is ok. Much more similar to bikepack events than a cross-country, downhill, or any other type of bike race.
That is a relevant distinction for events crossing BLM land because BLM has a general permitting process for competitive use (see handbook 2930-1). So the term "race" will immediately get peoples hair to stand up because it raises the specter of dozens of jeeps or motorcycles (or for that matter, 100 downhill bikes) tearing through the last habitat of endangered desert species. The permitting process can become very expensive very quickly if a dozen people need to look into environmental impact issues. A good reason to avoid the term "race" for bikepacking events, even though (like randonneuring), this is about getting from one place to another as fast as you can - and without big impacts on the environment. The National Forest Service requires permits if there are entry fees, organizers derive some income, or there are more than 75 people participating.
The history on how randonneuring became legally recognized as NOT being bike racing in France is also useful to know when organizing bikepacking events if anybody mouthes off about an "illegal race": follow the same idea and use the relevant language about "noncompetitive" on the organization site. Starting more than 100 years ago, long-distance, high-speed rides, often through the night, were used as "transport stages" before and after more gentle touring (no cars to take you to a trailhead). By the 1920s, this became formalized as "randonneur" brevets, where people could challenge long distances with time limits and there was an official umbrella organization. In the 1970s, the French Cycling Federation (in charge of bike racing) complained that these events are competitions and bike races and therefore either should be prohibited or only held by FFC. Now, randonneurs really hated that idea, probably just as much as if we had to take out annual licenses from USA Cycling, so at that moment, randonneur events were simply declared to be noncompetitive. A formality because the essential events continued unchanged. At the front of the pack, people hammer through randonneuring's prime event Paris-Brest-Paris in under 50 hours and it is just as competitive as anything; at the end, many struggle making the time cut under 4 days. No prizes, no awards (sounds familiar?). Same strategies as you would expect on a short bikepacking "race" (like Stagecoach 400, AZT 300). If you want to be in the lead group, it means little to no sleep.
Bikepack "races" (maybe we can find an alternative term) are much more in the original spirit of randonneuring than the more recent development in the US, which have become environmentally wasteful commercial enterprises, like RAAM or Furnace Creek 508, by replacing the idea of self-support with multiple cars idling behind each rider and "teams" where every rider just does a fraction of the distance. at the same time, I also hope they stay in the randonneuring spirit rather than getting swamped by big legal codebooks as the "real" cycling races on closed courses (whether dirt or road).