Liquidated damage payable by foreign exporter

Conventionally, LD amount gets adjusted thru invoice netting off or a separate remittance.

My query is

BOE gives a declaration about true price

LD amt thru banking channel stays unreglected in BoE, so Customs Dept is not aware though they get higher revenue

But our declaration about real price in BoE is diluted.

My feeling.. to be adjusted in exporter vendor's invoice itself, so that as Importer wr are protected and do not pay gst on LD on reverse charge method.

Kindly guide.