Original text:
routers; misbehaving middleboxes; and the potential use of Quick- Start to attack routers or to tie up available Quick-Start bandwidth. <del> 5.4. </del>  When the proposal relies on explicit signals from the path, the effect of traffic passing through the tunnel - where routers may not be aware of the underlying flow - MUST be considered. <del> 5.5. </del>  RFC4653 discusses the effect of extreme packet reordering. <del> 5.6. </del>  The proposal should consider how the alternate congestion control mechanism would perform in the presence of transient events such as

Reviewer comments:
Created a separate issue to discuss ECN.
The guideline section discusses "Investigating a Range of Environments", with a focus especially on "Random Early Detection (RED) ] and Drop-Tail." The IETF and the IRTF have produced several different proposals for Active Queue management, with somewhat different characteristics. Interestingly, there is a tension there between developing Queue Management that "plays well" with existing congestion control algorithms, and developing congestion control algorithms that "take advantage" of AQM. Not sure what to say there, but at a minimum we should develop expectations about "signals" produced by AQM (e.g., the ECN markings of L4S) and reaction by congestion control algorithms. To go further, the could be a discussion of "honest signals", such as delays, that are very hard to "fake" in routing nodes, other signals such as ECN marks that could be produced by the network at very little cost, and packet losses that fall kind of in between. But we are not writing for the IRTF, so this could be kept brief.
On the topic of AQM, IETF published Characterization Guidelines (RFC7928) and Recommendations (RFC7567) that could be exploited for further discussions in this work.
Martin and Gorry: add a reference to 7567 to AQM behavior and evaluation criteria, which is not in scope for this document talk about evaluating CC interaction with AQM
Something like "CCs should be evaluated against AQMs that are prevalent in the internet" -- is there a reference that provides a taxonomy?
Editors: FQ-CoDel, PIE, L4S (RFC9332) have RFCs Are the others that should be evaluated, and do they have available specs?
Discussed at IETF 118: Many operators are not particularly aware of AQM or these concepts in general Include FIFO in the list Also do at least an AQM "you should evaluate the scenario with FIFO queues and should also consider the impact of various common AQMs and run detailed simulations against them", while maybe name-checking a few particularly relevant ones. Yes, should have criteria for this, and also should not ask people to run NxN interop matrix. Out of scope to mandate AQM
I suggest: Probably ought to include a suitably configured RED also. ... and not suggest ALL of these need to be checked, more encourage consider AQM and FIFO scenarios.
I fixed a typo, but otherwise this looks good.

Revised text:
routers; misbehaving middleboxes; and the potential use of Quick- Start to attack routers or to tie up available Quick-Start bandwidth.  <ins> 5.5. </ins> When the proposal relies on explicit signals from the path, the effect of traffic passing through the tunnel - where routers may not be aware of the underlying flow - MUST be considered.  <ins> 5.6. </ins> RFC4653 discusses the effect of extreme packet reordering.  <ins> 5.7. </ins> The proposal should consider how the alternate congestion control mechanism would perform in the presence of transient events such as