"Opening a new tab from a container window opens a normal tab and not a
container tab"
I should note that the last comment on that issue was made in July, so I went ahead and commented asking about adding a setting to change the new-tab container inheritance behavior.
* CTRL-T opens in DefCon
* Right-clicking a link and selecting "Open in New Tab" opens in SameCon
That's what I would expect the default behavior to be.