I ski the n77's, no problems for me. Metal is the key here assuming the general condition is good.
In the end, they are your legs so do what you are comfortable with. Here is the old "self release check"
Proceed at your own risk.....
From the 1984 Geze in-box Consumer Instructions;
Unusually aggressive skiers and racers who sometimes need higher settings can use the Self-Release Method to obrtain these special settings. This method [conducted in the proper way] may help to insure that the special settings these skiers need will not be grossly overtightened, which is the usual case with adjustments made without using this method.
Start by using the presettings for [Type III+] skiers that are suggested on the Geze release setting chart.
— Stand on one foot with the boot buckled as it is during skiing.
— The ski should not be helf fixed.
— Release the heel by bending the lower leg forward (move the knee forward and down—toward the forebody of the ski). Do not lunge forward with the opposite leg because this will cause an undesirable upward pulling on the Achillies tendon.
— Readjust the forward heel release setting to your "comfort threshold".
— Place the ski on its inside edge by rolling the knee inward and then SLOWLY twist the foot inward. Rapid twisting should be avoided because it is not the worst case for maximum loading.
— Readjust the setting to your "comfort threshold".
If, based on further skiing, it is believed that higher settings are needed, the setting may be increased as long as self release is still possible."