playing with Akka.Persistence.FSharp's persistent view's manual updates

AkkaPersistentViewUpdate.fs

open System
open Akka.FSharp
open Akka.Persistence
open Akka.Persistence.FSharp

    
let system = System.create "sys" (Configuration.parse("""
    akka.persistence.view.auto-update = off
    """))

type Query = Query

let s0 = 
    spawnPersist system "s0" {
        state = []
        apply = fun m s e -> e::s
        exec = fun m s e -> m.PersistEvent (fun e -> e::s) [e]
    } []
let s0v =
    spawnView system "s0v" "s0" {
        state = ""
        apply = fun  (mailbox:View<obj,string>) state (e:obj) ->
            match e with
            | :? string as s -> state + (s.ToUpper())
            | :? Query -> 
                mailbox.Sender() <! state
                state
            | _ -> state
    } []
s0v <? Query |> Async.RunSynchronously |> printfn "%s"
s0 <! "foo"
s0 <! "bar"
s0 <! "baz"
s0v <? Query |> Async.RunSynchronously |> printfn "%s"
s0v <! Update()
s0v <? Query |> Async.RunSynchronously |> printfn "%s"