At that point can't you just store the output current in supercapacitors for later use anyway? You can even feed it into the machine itself. Supercapacitors easily have better than 20% efficiency for each cycle.

No, ITER doesn't have any planned way to make electricity, the power it outputs will be largely thermal and radiative. Engineers will likely put up a cooling system to measure the thermal output, especially after putting up the various ways to turn the major neutron radiation into heat (which is a fun way to produce energy with rare materials as a byproduct).

DEMO, to my knowledge, will then include an actual electric generator to be hooked up to the fusion core.