I don't see anything in what you posted that contradicts what I said. Several of the references essentially repeat what I said. The sources that you referenced primarily discuss how the charitable organization reports in-kind donations on its financial statements. That has nothing to do with whether the donor can claim a tax deduction. The criteria are completely different. You cannot draw conclusions about deductions by the donor from rules for financial reporting by the organization. Where your references do mention deductibility by the donor, they say the same thing that I said.
Some of the text on the Charitable Allies web site (your first link) is identical to text on the Labyrinth Inc. web site. Obviously one was copied from the other. They both say "Generally personal services are not deductible, however, the expenses associated with providing such services are." In addition, Labyrinth says "It's important to note that donated time (volunteering) is not tax-deductible, but if the volunteer provided goods to help complete the volunteer job, those things would be tax-deductible."
You didn't provide a link to the text that you posted "From another source." It's from DonorSnap, a company that sells software for non-profits. Here is the link.
In-Kind Donations: A Complete Guide
The links to Labyrinth and HBK come from the DonorSnap page. The text of the Labyrinth reference on the DonorSnap page repeats what I quoted above. Also, the example of the veterinarian at the end of the your quote from the DonorSnap page explicitly says that the vet's time is not tax deductible.
The HBK page (referenced by DonorSnap) is solely about financial reporting by the organization. It doesn't even mention tax deductions for the donor.
