Something else has to be going on here. A valve job won't destroy your rings, theres just no way if it was a proper valve job.. Are your oil sprayers working under the pistons? Are the pistons cracked from your ether spraying or overheating? Did your oil get some contaminate in it and take out bearings and rings somehow? Do you happen to have any of the oil left so you can send some to blackstone and see *** is in it?
Something just doesnt add up... Could your new valve guides/valves maybe have been misalligned or be the wrong size somehow and sent metal shavings into your cylinders destroying your rings? If the guides were shot that wouldnt show up on a compression test if the valves were still seating well enough to hold some pressure especially with your new stronger springs.
What stem seals did you use on the new valves? The same as a stock 7.3? I assume you replaced them \ installed them even though you didn't mention stem seals in your first post. If you didnt install any that might explain how you burned so much oil and maybe toasted the rings.
Anyways, just kind of thinking aloud here...