As you note, there's a difference between what's generally referred to as a Priesthood Blessing (administering to the sick GHB 18.13.1, or blessings of comfort and counsel GHB 18.14.1), and giving words of blessing. In the section on conferring the priesthood and ordaining to an office, in GHB 18.10.4 (who performs the ordinance) and GHB 18.10.5 (instructions), there is no distinction made between an authorized Priest and a Melchizedek Priesthood holder in who can "gives words of blessing as guided by the Spirit." (step 5 in the instructions)In this case, what about the step “give words of blessing…” ? I cannot find any general instruction on this.
Additionally, there is specific wording in GHB 18.10.5 that "An ordination is an opportunity to give a blessing." If a Priest was not able to give words of blessing when ordaining, that would seem to go counter to this specific instruction.