Fuji,
Do you know that the legal department added in that piece?
The placards in your aircraft are giverned by regulation - the certification standard and the mandatory ones will be listed in the Type Certificate Data Sheet.
You will find all the limits on the Type Certificate Dats Sheet.
You will not find the Stall Speeds there. Do you think that they are limiting in any way?
You will not find that airfeild performance figures there. Do they limit you in any way?
As I said near the start of the debate. Feel free to be a test pilot if you want. Check that test flying is permitted by the insurance policy because valid insurance is mandatory.
You might also like to check the legal conditions required for test flying especially the ones regarding the carriage of observers etc etc.
Regards,
DFC