Again this is based on the idea that targetinfo movement speed values under Indi-Gravity (or Geo-Gravity) in the presence of a geomancy debuff nerf / attenuation / resistance provide the actual resistance % that applies to all other geomancy enfeebles / debuffs, also accounting for the max effect of Indi-Gravity/Geo-Gravity.
Code:
Indi-Gravity effect targetinfo value % reduction Reduction as multiplier
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Lilith HTBF - any difficulty* 0%
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Shinryu HTBF - Very Easy -1.2 -44% 0%
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Shinryu HTBF - Easy -0.8 -36% 33.33% 8/12
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Shinryu HTBF - Normal -0.6 -32% 50.00% 6/12
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"Major NMs" in Sortie* 50.00% 6/12
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Dealan-Dhe - V+0 -0.5 -30% 58.33% 5/12
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Dealan-Dhe - V+1, +5, +10, +15 -0.4 -28% 66.67% 4/12
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Shinryu HTBF - Difficult -0.3 -26% 75.00% 3/12
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Dynamis - Divergence NMs* 75.00% 3/12
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Dealan-Dhe - V+20 -0.2 -24% 83.33% 2/12
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Shinryu HTBF - Very Difficult -0.1 -22% 91.67% 1/12
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Dealan-Dhe - V+25 -0.1 -22% 91.67% 1/12
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Odyssey - Sheol C NMs* 0 -20% 100.00% 0?
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"Fomor Summoner" Ambuscade 0 -20% 100.00% 0
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Note: For Shinryu VD I previously mentioned (miscalculated) 90% reduction a few years ago
Anything with an asterisk I have to verify myself.
Note that a weird thing with Dealan-Dhe is that the targetinfo value can fluctuate or not even change, e.g., I went in on V+20 the first time checking and Indi-Gravity wasn't affected for some reason (-44%) even after touching the mob. Then I went in on V+20 another time and it the targetinfo value was -24%. Some other times it even toggled between the resisted value and the unaffected value.