You want the metronome to count-in at the tempo change of the next bar? I don't think this is possible given the current implementation of the metronome/click in Logic. Tempo is a global setting and the count-in happens before the tempo change on the timeline.
I understand what you're looking for and there are more complex use cases like time signature changes...
One quick approach is to create a Software Instrument track with the Klopfgeist instrument on it. Create a MIDI region where the tempo changes (Exactly 1 or 2 bars as desired). Edit the region in the Piano Roll and add notes on the beats. You get a MIDI click at the desired tempo. Bounce in Place the region on a new audio track You then get an audio click region at the desired tempo. Here is the trick:
Open the region in the Audio File editor (or the Project Browser). You can see a small anchor icon at the bottom. Move it at right end of the region.
In the Main Window, move the region so the end of the region aligns exactly with where the tempo change happens. Now you have an audio count-in at the desired tempo change. Just deactivate the Metronome Count-In.
The same strategy can be used for more complex use cases like time signature changes.
If you have any questions, do not hesitate.
WD