Well, it depends on what you mean by "broken". From my perspective, as long as the code doesn't crash SMW's regular functionality, it's good enough. If there's a problem with the Site Settings functionality in SMW - even a severe problem - you could just redirect it as a Site Settings issue, which is really what it is.
The same thing holds true for Page Schemas, by the way - the code in SMW that hooks into it is somewhat complex, but as far as I know it hasn't required any special maintenance effort on the part of SMW devs.
> Unfortunately, there isn't yet a public example of an extension that hooks into Site SettingsJust from the description you provided, it is still not clear enough for me to say much about it.
The general concern with putting it into SMW is that this forces the people working on SMW to hold it into account. This means making sure it does not get broken when changes are made on the master branch. That is hard to do since it requires the Site Settings extension. If the code is really trivial, then perhaps this is fine.
Jeroen De Dauw - http://www.bn2vs.comSoftware craftsmanship advocate
Evil software architect at Wikimedia Germany