Sorry but this is just not true. Those 10000 are a cap on the value you can enter in that specific dialogue and nothing else. Any table values are simply stuffed into a float value and have no cap whatsoever.
And just to prove my point I set up a really simple test mission with one capship shooting an other capship.
Shields of the target set to 5000 and hp 50000. Target died in 20 seconds
Then with 10000 shields and same hp, target was destroyed in 25~30 seconds
Then with 15000 shields, 25~30 seconds
50000 shields, 25~30 seconds.
If you can't use it let me know and I'll build something else.
Can you do a normal build? I don't usually use inferno builds.