Help in Design Mode - Table Builder

We are doing some of the Report using JetReport Table Builder. However, there is something we can’t able to fix the problem. Can you assist us.
After we deploy the Table from Table Builder:
1. We want to set the profit and margin columns to be 2 digits decimal (Both Column is Formula). I tried to set it at the DESIGN Mode. However, when after refresh, it is still not formatted.
2. We also apply IFERROR in the margin column. It also not working. The output, didn’t shows the IFERROR function
3. Can we set the Subtotal instate of do the SUM for the column?
4. Our Inventory Qty and COST is in negative value, can we make it positive? I tried ABS Function but it is not working?

ALL of the above is done in one TABLE BUILDER.