Why is it that Inherit Alpha is disabled when Pass Through(the group layer feature) mode is activated?
Is there any particular reason? Or is it inevitable codewise?

It is inevitable: passthrough means the group has no pixels of its own, no projection.

Ok. Thanks for replying.
Is it also the same reason for that the layer modes are disabled when pass through mode is DEactivated?

They're not deactivated, they're composited separately. What passthrough does is make group layers a mere organizational grouping instead of separately compositing(that is, calculating opacity and blending mode) the layers.

So if you have three layers set to multiply in a group layer without passthrough, the lowest layer will act as a base that the top two are multiplied with. If you turn on passthrough, the first layer below that will act as a base the three layers in the group are multiplied with.

TheraHedwig wrote:They're not deactivated, they're composited separately. What passthrough does is make group layers a mere organizational grouping instead of separately compositing(that is, calculating opacity and blending mode) the layers.

So if you have three layers set to multiply in a group layer without passthrough, the lowest layer will act as a base that the top two are multiplied with. If you turn on passthrough, the first layer below that will act as a base the three layers in the group are multiplied with.

Oh, now I see how it is designed to work! Thanks.