No. The IRS will not understand the "boot" until you report it. I always report for 1031 and non-1031 the contract price which should match the 1099-S in the sale section and then any adjustments (selling settlement costs, 1031 admin fees, etc.) in the adjusted cost basis section.  That way the IRS matching program will exactly match the 1099-S to the tax return and no playing pen pals with Uncle Sam.