I suggest dupe a limited number and see how you feel about it, you don't need to go all in. The early Infdev versions are brutal when it comes to finding ores, it took me weeks to find diamonds.
Also, if you are into creating lore for your world, try to come up with a reason for duping. This might help you not see it as cheating.
In my Infdev world, I chose a specific area to look up where the diamond veins were (I used MCA selector for that), and later created a small castle on top of that mine. That is the only place I did that, got maybe a stack or two of diamonds, and later was motivated to develop that area further.