Runing Firefox Portable at the same time as running Comodo IceDragon (portable), is it a bad idea?

Running Firefox Portable at the same time as running Comodo IceDragon (portable), is it a bad idea?

Comodo IceDragon is a web browser that is based on Firefox, and it can be installed portably.

(Comodo IceDragon homepage http://www.comodo.com/home/browsers-toolbars/icedragon-browser.php)

I know there are reasons why Firefox Portable won't launch/run when another instance of Firefox is running (local or portable), but it will launch/run when an instance of Comodo IceDragon portable is already running.

Is this a case of Comodo IceDragon being different enough that it can't cause any problems for Firefox Portable, or is it that Firefox Portable doesn't recognise Comodo IceDragon as a version/variant of Firefox?