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So, if i understand it well, the best mode for games is with the filter disabled to get a 1:1 copy. Is this correct?
Yes.
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Another doubt: when I make an image with filter OFF (Size reported by hardware (your CD/DVD-ROM drive) will be used to get an ISO image) could it be incompatible with other CD/DVD-ROM drives because of that?
No problem(s) should be encountered.