OTPInput Autopostback - workaround or in future update?

[Nick]

I don't think OTPInput control has an autopostback and so I am using this code to call client event then do post back via hidden link button to my server side function. This is used for allowing a user to enter a three digit entry key number and doesn't require them to enter the numbers and press a button for speed. If the control had autopostback when all boxes have a value and the last box value is entered this would make the control much more useful. Is there a better way of doing this?

<telerik:RadScriptManager ID="RadScriptManager1" runat="server" />

<!-- OTP input for three digit key number-->
<telerik:RadOTPInput ID="otpKeySearch" runat="server" Placeholder="0-9" Space="true" Type="Number">
    <Items>
        <telerik:OTPInputItem GroupLength="3" />
    </Items>
    <ClientEvents OnChange="keyOTPOnChange" />
</telerik:RadOTPInput>

<!-- Hidden linkbutton we will post back to -->
<asp:LinkButton ID="btnOtpPostBack"
                runat="server"
                OnClick="otpKeySearchChanged"
                UseSubmitBehavior="false"
                Style="display:none;" />

<script type="text/javascript">
    // Fires every time the OTP value changes
    function keyOTPOnChange(sender, args) {
        var value = args.get_value() || "";
        // Only act once we have exactly three digits 0-9
        if (value.length === 3 && /^\d{3}$/.test(value)) {
            // Force a full postback to the hidden LinkButton
            __doPostBack('<%= btnOtpPostBack.UniqueID %>', '');
        }
    }
</script>

    ' Handles the hidden LinkButton postback
    Protected Sub otpKeySearchChanged(sender As Object, e As EventArgs) Handles btnOtpPostBack.Click
        Dim theKeyNumber As String = ""
        If otpKeySearch IsNot Nothing AndAlso otpKeySearch.Value IsNot Nothing Then
            theKeyNumber = otpKeySearch.Value.Trim()
        End If
        If theKeyNumber <> "" AndAlso theKeyNumber.Length = 3 AndAlso IsNumeric(theKeyNumber) Then
            ' get key number from database and perform redirect to keys panel of relevant entry dashboard
        End If
        ' If we got here (redirect above failed - value was invalid or key not found in database) show the radNotify with message to user
        notifyInvalidSearch.Show()
    End Sub