Yes I understand it, note I added the Template:Icon page back in 2011 based on old style wikitext templates, and due to how the template works (expensive in processing power which is why it is broken!); it is no use working on it until Mediawiki has been upgraded by @sam888 who can then install the Lua script extension and then we can convert the old wikitext templates into a Lua module scripts!
You can see the newer Template:Icon over on Wikipedia uses the Lua script.