Sorry to be so late to the party, but in case other people get this issue. ADB will often work just after the kernel finishes loading, before it gets shut off. So between the htc boot screen and when the boot anim starts you have a window to commit abd commands. I often use this to save time when flashing kernels etc, notably because my WIP roms rarely make it past bootanim!
HTC One V (unlocked ~ S-Off) - CM10 Final Rom - HellBoy CM10 Kernel