There are several MI
There are several MI BFRunners that are expert trail runners, a few that come to mind instantly are Jason R., sole_foot, and Smelph I believe runs trails barefoot as well.
Conditioning is important of course, and scanning the ground for objects becomes even more neccesary.
I only run trails in short sections that are included in road races, and I prepare for that by WALKING gravel and trails.
The longest trail segments I encounter in my 5K road races are 1/2 mile, and I always assume that injury is more probable than on the road.
The race you're planning on doing in Royal Oak this Saturday will be a good confidence builder, since it includes three seperate short sections of gravel roads, and one quick steep downhill on a grassy slope in a park that is covered with rocks and sticks. Only about 20 seconds worth, but a fun challenge to break up the road monotony. The three gravel sections also are only about 10-15 seconds each. The start and finish are in a park as well, and include about 20 seconds of park field w/ sticks and stones each.
Last year's Royal Oak race was in mid October, so possibly those sticks won't even be there this Sat.
That said think about this:
The Fallen Warrier 5K in Wyoming MI is in mid NOVEMBER!
At race start (9:00 am) typicaly the temp will be very close to the low for the day, which averages 31 degrees F. in mid November.
The odds of wet ground at that time and place are very high, and certainly autumn's winds will have knocked down plenty of tree twigs.
Can't remember if it was Ken Bob or someone else, but the saying " A numb foot is a dumb foot" comes to mind.
I would definitly plan on VFFs for that race and if it turns out to be non-numbing that morning you can always do it barefoot.
I've seen Jason run a 25K road race barefoot with a starting temp of a wet and windy 34 degrees, but he said it did take a few miles before the numbness went away. On a trail with objects on it numb feet might not make it past the first few miles!
"Shoes as tools when needed" is another saying who's author's name eludes me right now, but the Fallen Warrier 5K in Wyoming in mid-November sounds to me like it might be Tool-Time.
BTW, we spent several hours together last Sat and never ONCE did I see you lift your kilt nor sniff your fingers, so a MKG moment is probably unlikely.
I do worry about that possibility sometimes, like at the Soltice Run in Northville. The first half mile on the gravel racetrack, and the next 1/4 mile on the worst parking lot you've ever seen. I told my wife at the start that my goal was not to just finish, and that I would even accept injury, but PLEASE don't let me run past all the spectators at the end of the parking lot with blood pouring out from both feet!
Ran it last year and this past summer again, not a scratch.
I can for sure remember that it was Da Vinci that first observed that "the human foot is a marvel of engineering".