neandethal,
BMST, as an event, is an awesome site. Bikes riding to and from the start line to finish, in and out of impound and Scrutineering. Sometimes I just sit back and gaze at all the wild wonder.
No chase truck is REQUIRED, but please keep in mind the enormity of the event.
The pits are located at the Measured Mile, so if you're on the Mountain course, depending on where you start, you've got to ride the bike 1-2 miles to the start. Then you have to RACE your bike 2-3 miles and then turn around and either ride the mile or so back to Impound or start all over again. If you're running the International course, basically double that mileage. If you've got a high-strung race bike, you could be beating it up, riding it from Point A to Point B. A mile here and a mile there might not sound like much, but remember you'll be in 100?F heat under a blazing sun.
That said, I raced my bike without a chase truck in 2016 & on a rigid bike in 2017.
--Comet & me