This is what remains our fundamental difference of opinions.
Unless I am mistaken, you are only interested in an Eglinton line running in the underground portion from west of Keele through to Don Mills. In that situation, then yes, fully 100% grade separation has a good case.
But for those of us interested in seeing the line extend on the surface well to the west and east of those locations, there is still not the demonstrated discernible benefit to going hog-wild isolating the Eglinton-Leslie intersection given decent signal priority can achieve the same level of service speed at a fraction of the cost.
I would also like to see the line continue farther as planned, but I believe it would be beneficial to fix up the Leslie intersection because Don Mills will be a major transfer point and there will be significantly more rider west of it than to the east, this makes it a logical place to short turn half of the trains. Only so many trains per hour can run through a level intersection, and once service rises beyond this level it would have to be done at Laird instead, this is akin to short turning half of the trains on the Yonge line at Davisville when a significant amount of riders want to go to Eglinton.
Grade separating Leslie would also eliminate the need to build storage and crossover tracks at Laird, this would save a large amount of money as building them more than doubles the length of the underground structure needed.