Warning, RANT
While shaking down my new MTB for a few days, I encountered very few other trail users. Even so, at least 90% of those who I crossed paths with had little to no trail etiquette. Yielding to the uphill rider was accomplished by riding off-trail by the ignorant and/or inconsiderate instead of stopping and leaning out of the tread.
https://lnt.org/are-you-a-considerate-mountain-biker/
One person went so far as to be riding so far beyond their control and skills that they almost clipped me because they could not stop or slow down to avoid an uphill rider. Others were just not paying any attention to what was going on around them and getting them to yield the trail to allow a proper pass took a lot of patience. Another person had their dog with them and it came at me multiple times before I could get past them. The cherry on top of the stupidity was three goofballs who rode off-trail two times to "yield" to me as an uphill rider and added in the bonus of taking a break in the middle of a narrow portion of the trail in-between blind turns on either side. They scrambled to get out of the way, so I track-standed about five feet away from their cluster until they moved their dumb backsides out of the tread. I didn't say anythng to any of the offenders, but in the case of the three stooges it was close, "Y'all need to find another hobby." ran through my mind.
End RANT
The shakedown was a complete success. Most of what I was riding was a-technical, though unfamiliar. Days two and three had me loop back onto sections that I had previously seen and being more comfortable on the bike lent for ridiculous speeds when the trail opened up.