I asked you for a citation to show that all K players must be behind the free kick line BEFORE the RFP.
3-7-5. An entering substitute shall be on his team's side of the neutral zone when the ball is snapped or free kicked.
If the Kicker starts 5 yards in advance of the 40, and never gets behind the 40, he's considered a substitute, and we have illegal participation when he kicks the ball (9-6-3).
2-32-15. A team member entering the field to fill a player vacancy remains a substitute until he is on his team's side of the neutral zone.
(There is a player vacancy if there are less than 11 players on the field)
If you want to say that a player can TECHNICALLY be standing at the 45 when we whistle the ready-for-play, well, TECHNICALLY there could be nobody on the field at all. I don't understand your point - it makes no sense. Around our area, we are taught not to whistle the ready-for-play until both teams have 11 players ready behind their free-kick lines. If a team has only 10 players, the linesman/linejudge stay in the middle of the field. If it takes too long, we have a delay of game.