It is I imagine a difficult thing to really test with certainty. I just remember the discussion here where teh devs were quoted saying there is no mod to increase FD despite it being on some gear.
I spent a few hours roaming Karrus Hakrel last week in case though. 84% vs 53s would be a nice change, adn I'd live with 83.2% too

Not certain it would be worth removing lucent mitigation & APW ring but probably would if confirmed that they work.
If I get time this weekend I'll try FD-ing 100 times near an altar in APW to get some statistics.
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