Setting autorequest="true" shouldn't invoke doRequest oninit. That's what the request attribute is supposed to do.

<canvas debug="true">

    <!-- suppress spurious compilation warning -->
    <attribute name="validate" value="false"/>

    <!-- This should not invoke doRequest oninit, but it does. -->
    <class name="mydataset" extends="dataset" request="false" autorequest="true">
        <method name="doRequest" args="anArg">
            Debug.write("should not have been invoked. request is " + this.request);
        </method>
    </class>

    <mydataset name="mydset"/>
</canvas>

Compare to the way it should work:

<canvas debug="true">
    <dataset name="dset" request="false" autorequest="true">
        <method name="doRequest" args="anArg">
            Debug.write("this does not get called");
        </method>
    </dataset>
</canvas>

Workaround for now:

<canvas debug="true">

    <!-- suppress spurious compilation warning -->
    <attribute name="validate" value="false"/>

    <class name="mydataset" extends="dataset" request="false" autorequest="true">
        <method name="doRequest" args="anArg">
            Debug.write("this will only get called when request is true");
        </method>
        <method name="init">
            super.init();
            if (this.request) this.doRequest();
        </method>
        <!--- work to override setRequest in super class from creating
              delegate. -->
        <method name="setRequest" args="request">
            this.request = request;
        </method>
    </class>

    <mydataset name="mydset"/>
</canvas>