My take is that most of the classic Gym Jones or crossfit style power endurance/metcon workouts tend to be too short in duration to elicit the right training response. TFTNA M.E. work seems to be most cleanly characterized as: sport specific movement with a high (perhaps higher than the actual event) muscular load that lasts long enough to have an aerobic impact. Both the sport specificity and duration are often off in these workouts when RX’d.
But I think that they can be tweaked into being very useful training means with some thought (my guess is that this is most true when the objective is more intermittent/higher intensity than Liberty ridge though). Earlier this year when an elbow injury was keeping me from climbing, my M.E. sessions were a mix of long IWT’s and intervals using bodyweight exercises. For the intervals I tended to use lunges or heavy stepups (KB swings also seem like a good idea). I found 6×30:30 w/ 2-4 min rest to be good intensity level for 1hr progressing to 90-120 min sessions over 2 months. My first few sessions of these alerted me to some calf and hip muscles I hadnt felt in a long time.
Best of luck!