Hello Man Liu,
The minor releases are good enough for production release, because they are evolution of the Official release and the Service Packs, meaning that only bug fixes (that are tested) are released (through the minor release) and no new development code.
Yes, we will support a released hotfix (int. build), issues introduced in an internal build are usually solved in the next Official Release.
Just make sure that your product is stable with the hotfix and then it is safe to release.
All the best,
the Telerik team
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