Ok from this it's obvious you don't have knowledge of how hydraulic brakes work. Google it, take a class at your local community college, or stop down and bug your local auto shop. I'm not going to write a book here and teach you.
easy question.. should be an easy answer for you?
I've bled brakes manually and with a vacuum pump. had a chunk of ice take out the rear brake line on my truck, lost brake fluid, no rear brakes. once i got across the ice bridge... had hell of a time stopping the truck coming down the river bank after crossing the bridge. yup, had front brakes... good for stopping from speeds of no more then 20 mph, any faster I'd need 40 miles to stop her. would I drive hundreds of miles with no rear brakes to get to a shop for repairs.... not on your or my life! you offered to post a picture of said reservoir with a baffle... now your gonna take yer toys and leave the sandbox? :(
the point most, including myself are trying to make is ... open a bleeder when bleeding brakes manually and the pedal falls to the floor or as you said the master cylinder "bottoms out"... pedal pressure is reduced due to open bleeder or in OP's case broken brake line...
