Hi Dave,
I have watched the method in my local kitchen,
They will use a large wok and add the poppadoms two at a time, to the hot oil.
Before they are fully cooked they turn them over and finish for a few more seconds,
they then place the poppadoms on a plate and use the weight of a pan lid to flatten them out, as you say, before they are set.
This works perfectly well when doing one at a time.
Regards,
Mick