Well, I think those 16 questions are really there to give you a guideline. The thing is, if there are some of them, and you say.... As you pointed out, when there's only one option on the table, you need to ask yourself why there is only one option on the table and what was actually put out to support it, to document it.
I think it always comes down to those questions. What were the answers? What was documented in order to support the fact that you might have said that criteria do not apply because of X, Y and Z reasons?
I think you cannot push those questions away. On the other hand, you need to find alternative reasoning sometimes, such as that it's just logical, since there is only one supplier that can actually provide you that type of service. Before the pandemic, were there more? How come there's only one right now? Have some of them just gone out of business, or were they not interested? That could be a possibility, but you need to document and support whatever decision has been made.