In Impress, is it possible to change an existing shape (as per Powerpoint's "Change Autoshape")?

Instead of creating a new shape and copying over formats and text, is it possible to change a shape, whilst retaining the existing formatting and text? In Powerpoint this is possible as Change Autoshape, but I cannot see similar functionality in Impress - and I can’t see it as an explicit unsupported function.

Thanks a lot

Unfortunately I know of no way to change the nature of a shape from one type to another e.g., rectangle to ellipse, ellipse to hexagon, hexagon to arrow, etc. Drawn shapes in Impress (at least under v4.1.4.2) tend to use the draw:custom-shape element regardless of the shape being drawn. I am not sure why this is, but it is clear that a number of guesses / estimates would have to be made if an attempt was made to convert a rectangle:

<draw:custom-shape draw:style-name="gr1" draw:text-style-name="P1" draw:layer="layout" svg:width="2cm" svg:height="1.8cm" svg:x="1.6cm" svg:y="1.4cm">
    <draw:enhanced-geometry svg:viewBox="0 0 21600 21600" draw:type="rectangle" draw:enhanced-path="M 0 0 L 21600 0 21600 21600 0 21600 0 0 Z N"/>

… to a hexagon, for example:

<draw:custom-shape draw:style-name="gr1" draw:text-style-name="P1" draw:layer="layout" svg:width="2.4cm" svg:height="2cm" svg:x="12.2cm" svg:y="1.4cm">
    <draw:enhanced-geometry svg:viewBox="0 0 21600 21600" draw:glue-points="10800 0 0 10800 10800 21600 21600 10800" draw:text-areas="?f3 ?f3 ?f4 ?f4" draw:type="hexagon" draw:modifiers="5400" draw:enhanced-path="M ?f0 0 L ?f1 0 21600 10800 ?f1 21600 ?f0 21600 0 10800 Z N">
        <draw:equation draw:name="f0" draw:formula="$0 "/>
        <draw:equation draw:name="f1" draw:formula="21600-$0 "/>
        <draw:equation draw:name="f2" draw:formula="$0 *100/234"/>
        <draw:equation draw:name="f3" draw:formula="?f2 +1700"/>
        <draw:equation draw:name="f4" draw:formula="21600-?f3 "/>
        <draw:handle draw:handle-position="$0 top" draw:handle-range-x-minimum="0" draw:handle-range-x-maximum="10800"/>