Implicit Attribute of Index in Sample Index Node

In the past "Transfer Attribute" node contains an implicit attribute of Index. As they are split into various Sample nodes, Sample Index node lost its implicit attribute of Index. Index is so commonly used that adding the implicit attribute back will save a lot of linkages to improve the maintenance of node tree.

More importantly, if you want to use other index, it doesn't really increase the cost.

I don't really understand the justification removing it at the first place as it seems against the experience in the actual practice about how useful an implicit attribute can be in this case.