On the 282, depending on the power supply configuration you are using (single rail, 2 rails, 4 rails), you tend to be sharing the aux2 rails with other parts of the preamp. If you were using a Supercap or dual Hicaps to give 4 power rails with both upgrade 1 and 2 sockets being used then quoting the faq here for when all 4 rails are used…
Upgrade 1 socket powers the left channel: 729 input filter stage and tape buffer off one regulator. This regulator also powers one side of the aux2 output (for the right channel of a stageline), gain stage off the other regulator
Upgrade 2 socket powers the right channel: 729 input filter stage and tape buffer off one regulator. This regulator also powers the other side of the aux2 output (for the left channel of a stageline), gain stage off the other regulator
With a 252, you are connected to the Supercap via a Burndy cable and this provides two dedicated rails directly from the Supercap to the aux2 socket. Nothing else in the preamp utilises these rails.