Any idea why your plugin does not work on this code?

I am trying to insert an SVG image into a post. If in inadvertently open the WordPress Visual editor it rewrites my code. I have tried a half dozen plugins that claim they will prevent my HTML code from being changed but none of them seem to work.

Here is my original code:
<object type="image/svg+xml" data="image.svg">Your browser does not support SVG</object>

Here is what WordPress visual editor changes it to:
<object width="320" height="240" classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,40,0"><param name="src" value="image.svg" /><embed width="320" height="240" type="application/x-shockwave-flash" src="image.svg" />Your browser does not support SVG</object>

Any help getting your plugin to work on this would be greatly appreciated. Thanks.

http://ww.wp.xz.cn/plugins/preserved-html-editor-markup/