Fixed Asset Creation at the Invoicing stage

Our customer has below requests in creating FA object.

1. FA should not be created from PO (based on the asset value, it was not identified as an object initially) - Disabled the auto creation of FA in the PO line
2. Once the supplier invoice is received , the invoice value is >  PO value → Then decide to identify as a FA object.

Could you please advise what is the best way to achieve this.