People just have a non-specific idea of what diminishing returns means, and it's hurt by the use of percentages.
One console gives a total of +20% of X. Two consoles give a total of +40% of X. Three consoles give a total of +60% of X. That is not diminishing returns, because you are still getting +20% of X per console. Each additional console does not suddenly give less than +20% of X.
What throws people off is that the % in the description is additive, not multiplicative. They go "The 2nd console is only giving me +16%, not +20%! The 3rd console is only giving me +14%, not +20%!" It's a mistake bought about by combine a fuzzy concept of diminishing returns with percentages.
Assume X is 100. One console gives a total of +20. Two consoles give a total of +40. Three consoles give a total of +60. It's exactly the same scenario as the above, but now it becomes obvious there is no diminishing returns, you are getting +20 per console. Each additional console does not suddenly give less than +20.
The only thing that suffers diminishing returns is Damage Resistance Magnitude itself, not the consoles. What is displayed on items is "Damage Resistance Magnitude" (even though it's not displayed as "Magnitude"), but it shows "Damage Resistance" on our Status screens. The Damage Resistance Magnitude granted by consoles stack without diminishing returns, (1 = +20, 2 = +40, 3 = +60, etc.) but you get less actual Damage Resistance from each additional unit of Damage Resistance Magnitude.
So your Damage Resistance Magnitude increases linearly with each console, but you're suffering diminishing returns for the Damage Resistance Magnitude translating into actual Damage Resistance.
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