I just realized, the change I have to get used to is to start the clock on the R's signal on free kicks and PATs.
(For non-UIL folks that may be looking in, this discussion refers to game timing changes made by the UIL, for UIL (Texas HS) football only. Do not apply this discussion to NCAA football).
"On free kicks" is not a change. The change is for the first scrimmage down FOLLOWING a free kick. For that, the play clock is now a 25-second clock that starts on the referee's signal. This is reverting back to the way it was before 2018.
So, the 40-second clock is used for regular scrimmage downs, after the initial down of a new possession for Team B, or after the initial down of a new possession for Team A following any legal kick down, unless there is some administrative stoppage that requires the play clock to be set to 25 seconds and start on the referee's signal.
And, to clarify a specific situation, if there is a "A-B-A" situation, other than with a legal kick down, the play clock is 40, and starts automatically. Example: B99 intercepts A11's pass, then fumbles and A88 recovers while grounded inbounds. Ruling, A, 1/10 (or 1/G), spot of recovery, ready (40 and running). This is a new possession, and a new series, for A, but it does NOT happen during a legal kick down, so it is treated no differently than if Team A had simply advanced the ball beyond their line-to-gain (despite the change of team possession that occurred during the down).