Or perhaps it's more a question of how you operate the aircraft eg AOC vs private.
Most (at least all I ever flew) 25 A/C just have 25 data published and must be operated to this standard, irrelevant to status of ops.
Quite a few 23 A/C (such as the whole 23 Citation-Series) have only 25 T/O data in their manuals. As you donŽt have any other numbers, you need to operate as to satisfy these numbers.
You can operate a 23 with published 25 numbers to the 25 standard. Since you talk about the KingAir, Raisbeck offers 25 numbers for their retrofits. YouŽll find out, that a KA is a bad 25 performer, relatively speaking.
For AOC ops on a 23 A/C with 23 numbers, you use all engine take off distance to 50ft and multiply that by 1,15 - a complete meaningless number. Good thing that engine failures do happen very seldom in turbine engines. I venture the guess, that exactly this nonsensical number was an argument used by the single engine turbine commercial ops crowd.