I see that using "terminal length 0" on the 4.1.1.9 firmware finally works. I'm not sure about exactly which version introduced this feature, but it was certainly way over due!

But I think that feature only works with the M6220s and not the stand alone version.

Ah, good point. I missed the model number in the subject. Sorry!

My post got deleted. I supposed to have used offensive language. 
After careful inspection of my post, I have changed the possible offensive word into 'ludicrous'

I have heard from several people this is just a missing feature. 
And I guess no one knows another way of retrieving command output other than using a ludicrous expect script like I did. 
I do have a working expect script now, but I cannot understand why vendors don't 
implement some xml/json webservice over https

I would like it as well if the Dell 6248 firmware was updated to allow for this option.

It would make capturing the output a lot easier!