GPS as ALT_SOURCE and Use Best option

ArduCopter Copter 3.6
1

Hi,

I’ve an Here2 connected as GPS1 and a a RTK solution as GPS2.
I’ve defined GPS as alt source.

I’ve understood that the “Use Best” option will always select the highest mode (so in my case if the 2nd GPS has RTK fix or float it will be always the primary GPS).
What about the Alt_Source? Can you confirm that the alt_source is using the same logic? So altitude will be taken from the best GPS?

Best regards,
Ced