I thought everybody interpreted 25% or max motoring whichever comes first .
OK, I see your point, you say "if max motoring is much lower than 25%, then damage could result". You are right! They should specify what is the minimum value to turn the fuel on.
But actually, unless you have some damage, if the rotors are free, you won't get an N2 that low.
I've had bad APUs, unable to reach 25%: in that case the trick in a turnaround was to motor until the EGT dropped below 180°C.
That worked to keep the peak within limits.
Of course start by removing all the electrical load possible from the APU gen.