Clarification: keyless list handling

[gsindigi]

Looking for guidelines on handling keyless lists e.g., /network-instances/network-instance[name=vrfInst1]/protocols/protocol[identifier=BGP][name=bgp]/bgp/rib/attr-sets/attr-set[index=1]/as-path/as-segment. This list is defined without any keys. Below is a definition tree of the same. There are other occurrences as well.

...
        |        +--ro rib
        |           +--ro attr-sets
        |           |  +--ro attr-set* [index]
        |           |     +--ro index                                             -> ../state/index
        |           |     +--ro state
        |           |     |  +--ro index?              uint64
        |           |     +--ro as-path 
        |           |     |  +--ro as-segment* [] 
        |           |     |     +--ro state
        |           |     |        +--ro type?     oc-bgpt:as-path-segment-type
        |           |     |        +--ro member*   oc-inet:as-number
        |           |     +--ro as4-path
        |           |     |  +--ro as4-segment* []
        |           |     |     +--ro state
        |           |     |        +--ro type?     oc-bgpt:as-path-segment-type
        |           |     |        +--ro member*   oc-inet:as-number
...

Openconfig style-guide explicitly mention how to handle keyless list. However, I did not see any mention of atomic around such lists; this is in openconfig-rib-bgp-attributes and related yang files. Moreover, there is no clarity on how these are encoded as gnmi.Updates for a gnmi.Get/Subscribe, especially when such list contain more than one elements. As the key is absent, the resulting path for different instances will always be same !

Additionally, how a gnmi.Set should specify any values for such lists (assuming they exist in config path as well)? Will it be always going to be an overwrite operation for both Replace/Update cases ? If the list contains more than one instances, how are they to be specified?

When tried YGOT's TogNMINotifications , it results in an error as "unimplemented: keyless list cannot be output" as detailed in TogNMINotifications: Option to ignore unsupported fields

Does this mean such key-less lists cannot be encoded as gnmi.Notification's gnmi.Updates ?

Any clarifications/examples on this front will be helpful.