I know you've posted variants of this question elsewhere, but I haven't followed the results. That said, yes the 2206 will perform well as a mid bass driver in a compact enclosure.
I think that if you can get another LE85/2420 and 077/2405 driver you can make this work. You'll need to develop your own low pass section for the 2206, but you can use the rest of the Nelson Pass L-300 network and should get just what you need.
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