I can confirm I did not find a way to view or export priv key from specific address

Can only import one via dropdown menu in 'Tools'
'Sweep Private Key' 

 cc: @craigraw 

 Did you try this? Does it sweep to a new pubkey of your opened seed or does it really import the pub/priv keypair of an external seed? 

 So far for me only imports and exports whole seed. Not specific address