It makes me think, and it might not be as simple as reading the example explanations in this article, that the author could allow the person running his emulator to tweak some options. Heck, since the game database is pretty limited and known, some optimisation, which keep the playing accuracy (or not) could be applied. You don't know the game in the database? You apply fully accurate mode to be on the safe side.
For example when BYUU said this "When it comes to video, 99 percent of games do not try modifying the display registers while the screen is drawing. This allows entire scanlines to be drawn at once, requiring 262 scanlines * 60 frames per second of synchronization. But run a game like Air Strike Patrol, which writes to the display brightness register multiple times per scanline, and you must synchronize after every clock cycle if you want full accuracy."
Based on this, 99 percent of the games could apply some optimisation which could hopefully keep all as accurate to the original playing experience without doing useless computation for the "user" of the emulator. While if it runs an exception, like "Air Strike Patrol", it could default to the most accurate mode.
I think like an user here. Without knowing the in and out of how the emulator works, I don't know if it can easily be controlled with a couple of options that we can turn on and off. But if it could be done, then the accurate emulators could appeal to both the user who search a speed emulator and the most accurate in the world emulator.
