subdoc Durability code not supported?

Seen while resolving DOC-8975. Several examples in subdoc.js example don't work and I've fixed, but with 2 outstanding:https://github.com/couchbase/docs-sdk-nodejs/blob/release/3.2/modules/howtos/examples/subdoc.js#L221-L240
 
1) mutate-persistto example:
Passing either of the options gives ERR: Error: unimplemented functionality
It looks like these options aren't valid in the TypeScript either? 
I may be reading this wrong, I don't know TS..., but certainly
https://docs.couchbase.com/sdk-api/couchbase-node-client/classes/MutateInSpec.html#insert doesn’t implement 
https://docs.couchbase.com/sdk-api/couchbase-node-client/interfaces/InsertOptions.html

 
2) the mutate-durability example fails too, with ERR: [Error: LCB_ERR_KVENGINE_INVALID_PACKET (1031): A badly formatted packet was sent to the server. Please report this in a bug]
I know we had this error in beta with some collections calls, but this is different scenario and I'm running against Enterprise Edition 7.0.0 build 5302 
 
I've commented the 2 examples for now from the code to ensure it runs, but should either fix the code, or remove from the docs too, if it's no longer supported?