Self-equilibrated body, Hmm no clue as to the meaning of that word and perhaps an interesting concept but in the real world if you are going to static flight load test then the full gross weight of the aircraft is included. I am no engineer but this was the procedure that I used with the one full scale airplane that I built in the experimental category and accepted by our FAA

Actually here in the US depending upon the category a general aviation civil aircraft is to be certificated in (standard, ultility or aerobatic) an additional safety factor is imposed as a percentage over the specific limits for each category

Now in the case (in the US) in the experimental category and in the case of a model airplane you are the engineer and can make the decision on how you are going to do such things as well decide on your own limits.

I would be pleased to hear about such regulations that may or may not apply to especially the giant models in your country. it is fascinating how especially some countries in Europe have very liberal laws concerning the giant scale stuff.

John