Not sure if my problem is related, but for me there is also no progress bar showing up:
I have max_execution_time set to 30 seconds, but of course the bulk optimization takes longer than that. So it interrupts and i have to click presume each time. It would be very convenient if the bulk optimization page could do the optimization with some ajax stuff, so that each image optimization is done in a single request.
Or will it work already this way as soon as the progress bar is functional for me?