TT who claimed that BBR's compression is insecure in some grand degree?
You are confusing trust model with being insecure, so you are misquoting, unless tacotime said something else I'm not aware of.
In any case, no tacotime was not one of the people who has claimed no exploit in KGW (that I'm aware of, but indeed maybe he has, it wouldn't surprise me).
KGW clearly has an exploit because it is thresholded at an exponentially declining well. So if you have enough hashrate, you can drive the hashrate adjustment at the time of your choosing. So you can ramp it up very high, then pull your hashrate slow enough to mine a secret fork while the hashrate doesn't adjust.
This needs to be quantified to be real. If the hash rate you are using to drive and then pulling is large enough, this adds little to the well known greedy mining or 51% attacks. If it can be done with less, then it would be significant.
Anyway, I'm not particularly interested in KGW specifically, but it is a good example of an area where vague claims are made on both sides without specific proof (again on both sides), and it is impossible to tell who to believe without solid facts.