I am not sure what that means. (Sorry.)

What happened to me:

I sent from address A to address B with change C which had low fee and stayed unconfirmed for hours.

I then wanted to sent something to address D. Instead of using address E with confirmed bitcoins, electrum decided to post it from the address C, so I had to wait until the first transaction confirmed.

That's why I am saying Electrum should prefer using confirmed inputs as outputs.