Your analysis on the surface seems to make sense; however, applying more simple logic says it cant possibly be correct. Besides the surface, all other things being equal, there is almost no way can say there is a difference of 10 seconds in the time it takes someone to cover 140 meters. Unless Lane walked the last 140 meters, Usain Bolt on a track could not create a difference of 10 seconds in a 140 meters. If Lane finished strong, the difference is probably no more than a second or 2. (Occam's razor)
Another way of looking at this is, there about 35 increments of 140m in 3 miles, to say there can be a difference of 10 seconds in 140m because of the surface, would be the same as saying there can be a difference of over 5 minutes between a slow and a fast course. The difference between slow and a fast course is usually about a minute with is a little over second per 140 meters, which again points to the difference between old and new course is probably no more than a second or 2. Last, but not least, I put the result's of 2016 D1/D2 Individual Sweepstakes and 2017 into a spreadsheet. I eliminated what appears to be the outliers and did an average and the difference between the races was only 1.44 seconds, which again points to the fact that the difference is probably no more than a second or 2.