I was thinking - maybe the generator (or constructor) can opportunistically lengthen runs so that there are more opportunities for using them for exclusion. You know the bread and butter for sudoku solving - the pair of pencil marks that excludes a number along its row/column. If that's done, maybe the puzzle can be made harder in other respects, like removing clues.

I solved today's puzzle, it's nice. Of course missing the "QoL" features of the popular solvers (I'm not a daily sudoku solver right now though)