I read through the composer documentation with fresh eyes today and it seems to match what I was thinking. If I understand your explanation correctly, the alias should be along these lines:

~~~~
      "dev-3.3/develop":  "3.3.x-dev",
      "dev-3.4/develop":  "3.4.x-dev"
~~~~

I'm heading out for a bit today but if you haven't gotten a chance to reply by the time I get back tonight I'm going to merge your PR and make that change myself… hopefully I'm right. Then I'll set up the needed stuff on packagist and we'll be ready for a `3.3.1` release :D

Thanks for all the help!