Balancing SE and HoDoKu scores for an "Expert" tier?

Hey everyone,

I’m currently building a Sudoku generator and trying to fine-tune the difficulty rating thresholds. I know generators exist already, but that does not make it less fun :-)

Right now, the "Expert" difficulty require a minimum of 3 "advanced" techniques (e.g. Skyscrapers, XY-Wings, Finned X-Wings). My concern is mostly on the HoDoKu score.

Some puzzles come out around SE 5.5 but rack up a massive HoDoKu score of 2700+, as the engine requires 3+ advanced techniques.

Aiming for a 3-tier difficulty system (Easy, Intermediate, Expert), so I have a few questions for you seasoned solvers here:

• Does a flat requirement of 3+ advanced techniques push "Expert" too deep into "Nightmare" territory for a general audience?
• Should the requirement decrease to 1-2 distinct advanced techniques to keep the solve satisfying rather than exhausting?
• Would a limit on the total advanced (not distinct) techniques used make sense?
• When you click "Expert" on a Sudoku game, what range of SE/HoDoKu do you actually expect to encounter?

Would love to hear your thoughts on how to balance this properly.

Thanks!