Add Subtotal Breaks

I’m looking to add subtotal breaks to my invoices to break down charges in groups, is that possible? For example,

Section 1
Line 1
Line 2
Section 1 Subtotal

Section 2
Line 1
Line 2
Line 3
Section 2 Subtotal

Grand Total/Balance Due

Also, is it possible to remove the main subtotal field? As I don’t charge tax, that field is redundant with the “Balance Due” field.

Sorry, I don’t believe these changes are possible.