another thing to mention unrelated to the tax, the price you (omni) buys compact gems for is a bit underwhelming compared to rough gems.
Assuming I mass produce compact gems the math would like this:
I sell 360 rough gems:
270c*360 = 97,200c
I sell 50 compact gems:
1530c*50 = 76,500
So conclusion I make roughly 20,000 more by selling them rough, and this is without adding in fuel for spark, I wouldn’t think this is your intention but feel free to correct me.