I understood the parent post to suggest dual licensing where the commercial license also gives you paid support. I.e. if you expect support pay up by buying a commercial license. Though I see no reason to conflate the two things. I would suggest in this case not even having a public issue tracker, and make your open source offering a take it or leave it proposition.

It sounds like otrahuevada is describing the same thing, doesnt it? Choose a commercial license if you want support, or the open source license if you don’t. That is how I understood it.

What otrahuevada is describing is a situation in which the software developer determines under what terms a particular user may use the software, not a situation where the user makes this choice. Only the latter situation is (can be) dual licensing. The difference may seem subtle, but it's actually huge.

There was a discussion about this with someone else just yesterday. I'll find the link.

Edit: https://news.ycombinator.com/item?id=29871302#29873586