I absolutely concur with your assesment. However, what if an agency uses LPTA? What if the lowest priced offeror is found technically unacceptable? Shouldn't that offeror or any offeror for that matter be given an opportunity for a debrief, notice of what led to an unacceptable technical rating, and to "cure" their proposals for future orders?
Seems to me that if agencies don't have to provide unsuccessful letters or conduct debriefs on orders under $5M, they essentially have carte blanche to award to whomever they like (typically, this means keeping the incumbent in place).
The problem here is that I think this provides a way for "smart" CO/KOs to circumvent FAR 6 and 15 by citing the "Ordering Procedures" of Part 16 after establishing an ordering vehicle. I understand what you've stated above, and if the IDIQ is for supplies or severable services (non-complex) than I agree. However, I do think this is very likely being abused. Thoughts?