So if we had a 440% luck round, you would be paid the shares you submitted that round plus round shares that are still on the shelf from say a 25% luck round, or what have you?
Yes.
I'll just clarify that not all shares from the 25% round would be paid (yet) in this scenerio.
A 25% luck round, as per luck in wizstats, means that the round took 4x as many shares as expected, earned the normal 25 BTC but 75 BTC in shares were shelved for a total of 100 BTC in shares submitted. A 400% luck round would be 1/4 of shares expected paying 6.25 BTC to pay off all shares submitted this round, and 18.75 BTC towards shelved shares. (I changed it to 400% from 440% for simplicity). No more than 25 BTC (+txn fees) can be paid per round. So, in this example of a 25% round then a 400% round, 50 BTC are paid out. 25 BTC to those working on the 25% round when the block was found, 6.25 BTC paid to those working when the 400% block was found, and 18.75 BTC paid towards the shelved shares for the 25% round, leaving 56.25 BTC in shares shelved still from that round.
Hope that makes some sense.