Start up condition of I/O pins

To extend @kennethlimcp 's answer, on D pins there is (or may be was, if this got fixed without me knowing) one very short moment before these pins enter stable high impedance mode where these pins go LOW very briefly.
So if you got any circuitry that would have problems with that you could either move this over to an A pin, or apply some HIGH triggered enabling logic.

Something to read in connection

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