In the absence of 'hard data' on the real Camel with regard to this phenomenon the issue moves away from a numbers game and becomes one of judgement. I'm sure HiTech and his team are far more capable and experienced at in game research, development and testing than I am. Hopefully they might take a quick look at the problem (Dr1 dominance), the possible cause (lack of or insufficient gyro effects in Camel) and decide (based on the anecdotal evidence) to tweak the FM a little, not so much perhaps as to induce Camel drivers to turn right 270 degrees instead of turning left 90 degrees; I think too much realism would deter even more players from flying it. But just enough to give it a bit more of a fighting chance.
I don't quite see how this kind of layout helps aircraft to have faster turn rate or radius in a sustained turn. Except small benefit of keeping the moments arms between center of lift and center of gravity as small as possible (almost non existant?). The (in)stability helps the aircraft to respond quicker to control input and therefore helps to intiate the starts of the maneuvers quicker (ie. instantanius turn rate) but again, I don't see how it helps once the turn enters into the sustainable region. I think you are drawing wrong conclusions from these anecdotes. This type of instability definately adds to the 'percieved' maneuverability through keeping the controls light and very responsive but it basically does nothing to make the sustained turning radius smaller for example.
Ok Wmaker if you own a gyroscope feel free to try this, if not I guess you'll just have to take my word for it. Spin the mass and hold the device arm outstretched such that the mass is turning clockwise from your perspective looking at it from 'behind' (along the axis of rotation). This corresponds to the rotation of the rotary engine in the Camel. Now move your arm stiffly right and left. You should notice some tendency for the device to pull or twist up when going left, and down when going right. This moderate effect known as precession replicates the type of reaction we see in a rotary engine aircraft configured normally, i.e. the engine is way out the front well clear of the centre of gravity, which has been moved rearward by the various other large masses being spread around to create a CG roughly one third the chord back from the leading edge of a wing (pair of wings CG position more complex especially if staggered) situated appropriately further back along the fuselage.
In the case of the Camel however, most of the mass was packed into the nose. The wings were well forward to compensate (bringing the wings to the CG as it were) so much so that the aircraft flew generally 'tail heavy'. So the mass is concentrated close around the CG. To replicate the gyroscopic effects in this situation run the experiment again but this time turn the device right and left using your wrist. You will notice a much more powerful tendency for the device to twist up when going left, and down when going right. Now hold the frame of the device from the side, such that you are looking across the axis of rotation with the left side of the mass moving toward you (i.e. replicating looking down on the Camel from above). Spin up and twist the device clockwise and anticlockwise using your wrist. Notice that the left side of the device pulls or twists down (away from you) when turning the device anti-clockwise, and up (towards you) when turning clockwise.
So the combined effect of the gyroscopic phenomenon in the Camel would have been a tendency to go outside wing high in the turn (which assists in both directions) but nose high in a left turn forcing adverse control input in pitch (stick forward) and extra input in yaw (left rudder) to hold the nose. In a right turn there would have been a requirement for extra pitch input (stick back) and adverse yaw input (left rudder) to hold the nose, but in this case the 'adverse' yaw input is actually a misnomer as it would actually result in simply less right rudder input, and you would generally be wanting the nose to stay down anyway to maintain your speed.
The overall result then is to produce somewhat clumsy turns to the left but rapid turns to the right, and on second thoughts I do believe these would have been sustainable. So long as the motor is still spinning the forces would continue to apply. I doubt very much if hard data existed back in the day (WW1 pilots would have paid scant attention to them anyway), the effect was pronounced enough to have given the Camel a reputation as a dangerous machine for the novice, and induced many of its' pilots to turn right 270 degrees rather than turning left 90 degrees fighting the stick. The Dr1 spinning a lighter mass placed further away from the CG albeit at similar rpm would likely have experienced significantly less of this effect, much like the initial experiment with the gyroscope at arms length, which would explain why the effect seems never to be mentioned in respect of the Dr1 in the available literature.
So I guess the question remains, has this been modelled accurately, or even should it be? Clearly that's not my decision to make, but I suspect that anyone who takes the time to fiddle with a gyroscope and look closely at the evidence will have some thinking to do.