Brianna, in reading your Dad's blog, I enjoyed that additional window into his+your thinking. For example, I thought that taking advantage of I-93 as an 'AT trailhead' coming off of Flume was very out-of-the box - though after doing this, would you still deem a Flume Slide Trail descent to be superior to an Osseo Trail descent [a super highly runnable trail though 1.6 miles longer]? Or was the Flume Slide down-climb the "right" kind of change-of-pace in exercise modes after running a lot of the ridge?
Given the weather conditions you dealt with for part of the trip and various opportunities for further optimization that no doubt occurred to you both through the course of the endeavor, it seems as though there's the potential for a substantial further pushing of this FKT envelope should you decide to do this again under the auspices of a more cooperative Mother Nature!
The only part of all the reading that I didn't enjoy as much was the part about your Dad wounding himself -- and seeing the photo of your blistered foot (Eeeewww!). I hope you both are healing well!
Alex