WGS84 - based map-extent does not zoomTo() correct bounds

[prushforth]

This extent

<map-extent units="WGS84" label="Spearfish roads" checked="checked">
    <map-input name="z" type="zoom" min="0" max="21"></map-input>
    <map-input name="xmin" type="location" rel="map" position="top-left" axis="longitude"
        units="gcrs" min="-103.8777946831626" max="-103.62268570651196"></map-input>
    <map-input name="ymin" type="location" rel="map" position="bottom-left" axis="latitude"
        units="gcrs" min="44.3728896172632" max="44.502173963810456"></map-input>
    <map-input name="xmax" type="location" rel="map" position="top-right" axis="longitude"
        units="gcrs" min="-103.8777946831626" max="-103.62268570651196"></map-input>
    <map-input name="ymax" type="location" rel="map" position="top-left" axis="latitude"
        units="gcrs" min="44.3728896172632" max="44.502173963810456"></map-input>
    <map-input name="w" type="width" min="1" max="10000"></map-input>
    <map-input name="h" type="height" min="1" max="10000"></map-input>
    <map-link
        tref="http://localhost:8080/geoserver/sf/wms?request=GetMap&amp;crs=MapML:WGS84&amp;service=WMS&amp;bbox={xmin},{ymin},{xmax},{ymax}&amp;layers=roads&amp;format=image/png&amp;width={w}&amp;styles=&amp;language=en&amp;version=1.3.0&amp;transparent=true&amp;height={h}"
        rel="image"></map-link>
    <map-input name="i" type="location" axis="i" units="map"></map-input>
    <map-input name="j" type="location" axis="j" units="map"></map-input>
    <map-link
        tref="http://localhost:8080/geoserver/sf/wms?request=GetFeatureInfo&amp;query_layers=roads&amp;crs=MapML:WGS84&amp;bbox={xmin},{ymin},{xmax},{ymax}&amp;language=en&amp;cql_filter=&amp;version=1.3.0&amp;transparent=true&amp;service=WMS&amp;layers=roads&amp;width={w}&amp;x={i}&amp;feature_count=50&amp;y={j}&amp;styles=&amp;info_format=text/mapml&amp;height={h}"
        rel="query"></map-link>
</map-extent>

is represented correctly in debug mode:

but when you zoom to the layer, or extent, it goes to too large an extent, not centered on the red rectangle: