I can imagine some cases where this might be necessary. But giving the middle finger to Travis leaves a bad taste in my mouth. Especially since the free offering is so generous and the 10 minute restriction seems completely reasonable.
The use case mentioned in the readme seems perfectly reasonable and there is little that you can do to fix it. AMI building at AWS just takes time. The only party that could reasonably fix it is amazon. Travis provides the capability to extend build times as well but the function provided makes it hard to tell if the build process is actually running - so this seems like an improvement.
However, never timing out stuck builds clearly is an issue, so I filed a ticket for it.