ArduPilot Custom Firmware Builder IST8310 compass missing in copter 4.5.7 and below

Hello,

when compiling a custom firmware (Copter 4.5.7) for my board (KakuteH7Mini-Nand) with an external IST8310 compass I noticed that the IST8310 is not listed under “compass”. There is only the IST8308.

This also seems to be the case with all other copter-versions below 4.5.7.
However, if I select version “beta 4.6.0” or “latest” the IST8310 shows up.

Plane seems to be unaffected as the IST8310 is also displayed in 4.5.7.

Am I missing something or is this a bug?