Art wrote:
"The capacitor is limited with respect to energy it can retain so what
happens when that limit is reached and the forward period has not come
to an end?"

There is a sudden flash as energy jumps the gap between the plates.

The energy a capacitor can store expressed in joules is equal to its
capacitance in microfarads times the voltage (squared) across its plates
divided by two million.

For a fixed capacitor, the only vatiable is the voltage. So, the greater
the voltage across the capacitor the greater the energy it stores. The
only limit is the breakdown voltage.

Best regards, Richard Harrison, KB5WZI