We need the quote_amount_c field to be a dependent calculation.
For records created prior to Jan 1, 2021, the field should be available for manual entry (no calculation applied).
For records created after Jan 1, 2021, the field should have a calculation applied. The formula I had in there before today was rollupConditionalSum($m01_sales_m01_quote_document_1,"quoteco_amount_c","roll_up_check_c",true). This should still work but it needs to run based on the Sale record's creation date.
For this one we need 150 should be pulling into the parent record: