This demonstrates why I'm uneasy with having two ways to set the value to indeterminate.

Note that dijit ProgressBar deprecated the indeterminate property and instead you are just supposed to use value (see https://github.com/dojo/dijit/blob/master/ProgressBar.js#L25).

Admittedly, value=Infinity is arguably non-intuitive, but it simplifies things.

What do you think about getting rid of the indeterminate property altogether?