Hi Pierre...
I think you echo my point, which you summarise well with:
over published gross and will continue to do so and if managed sensibly, it can be done.
A limit (Gross Wt, CG) is there for a reason, and if that reason is understood, and mitigated against, then a different limit might be appropriate if flown in a different manner.
This is seen with Aerobatics, Utility, Normal categories. You have shown it again with your:
The problem with a bigger than normal gross weight, is what you do with the airplane in that condition. I have to make gentle turns and easy pullups from the field until I lighten up.
The "problem" I see with the RVs is that plenty "invent" a new Max Gross Weight, over and above what Vans recommend. However, they (typically, there are exceptions) give no justification as to why they know better than Vans, do not specify (nor probably know) which parts of the structure or operating envelope the Vans limits apply to, and do not apply any mitigations (whereas you have) as to "how" they will operate, say between the Vans Gross Wt and their declared increased one.
An example might be if one had researched, say, the Vans RV-8 Gross Wt (1800lbs) and determined as far as 'g' limits went, then ~2180lbs Gross was fine for Utility 'g' limits, based on extrapolating the 1600lb/6g aerobatics limit - so a 2000lb gross is not an issue for Utility. You could even go to 2500lbs under Normal. However, this does not allow for "where/how secured" that (extra) load is of course.
However, we now have an issue with brake energy, wheel/tyre loads, and/or landing gear strength. These again, can be mitigated with upgraded components, or handling limitations (yes - can take off at 2100lbs, but MLW still 1800lbs except in emergency / smooth / long landing surface / post flight inspection).
I, for one, would have no problem with people, where permitted (e.g. USA) in increasing Max Gross if I saw a process to determine it somewhat more complex than plucking a figure out of thin air
And that such an approach to safety was behind the aims of the
http://www.rvflightsafety.org/ - instead we see comments such as:
The problem was flaring to land, the passenger couldn't get his gut in enough. I wound up wheel landing it after going around and beating him in the gut with the stick.
What happened to the "full & free" control check prior start and takeoff
310 for passenger / 350 PAX
What allowance was made for the seat belts and attachments here? Was the pax briefed that in the event of an accident, the probability of injury or death was significantly increased since at the design accident 'g' loadings, the seat belts would almost certainly fail?
you owe it to your passenger to ballast the airplane to that weight and fly it before you carry the passenger
Whilst this mitigates one element (handling) it does not the crash scenario - unless you are willing to subject your aircraft to destructive testing.