New Octane output is a great addition but there are some issues when using this output when saving renders:
1. When rendering animation, along with file in Octane EXR file format, Blender also saves another file with a format selected in Output rollout, like jpg or tif.
2. It is impossible to save Octane format when rendering a still. Pressing Shift+S in render window gives you an option to save only standard Blender formats.
3. When rendering animation, there is one unnecessary file saved without any number. It is the same as the first saved file in an animation.
4. File numbering with Octane format starts with single digit. It would be great if it used more digits like 0000, 0001 etc or if there was an option to set own pattern.
5. There is an unnecessary "octane_export" word added to a filename.