As a former Scout leader I can well understand the scheduling conflict. Seems like no matter what I wanted to do there was always somewhere else I could be by need or by choice.

I'd opt for the Burns Dinner which is only once a year. You wouldn't be the first Scouter to miss a training session - everyone has conflicts at one time another (to include anniversary and birthday celebrations, vacations, work, and even other Scout events). You can always attend the training at another District (or reschedule it if you're the trainer).