I'm just worried about the fact that it can be damaged on the larger bandwidth.
may be input amplifier will be overheat or ADC or etc (on larger frequrencies) and radiator is not installed for 1054 modification or other ..
I just do not believe in miracles
I guess you keep asking and doubting again and again, its clear you just want answer that what ever you wanted to hear.
Fungus already helped you, and in this forum here, especially in this DS1054Z matter, I believe that he knows what he is talking, and that include alot of hundreds or even thousands of DS1054Z owners that hacked the scope up to 100MHz.
Remember, you still don't own it, and I guess never used it too, so stop pretending that you know better than most of us DS1054Z owners here.
You're on your own and suggesting DO NOT buy it.