When I top feed, I release the blade from both clamps, thread the blade through the piece and table hole and then reclamp the blade. Sounds slow and awkward, but I can do it pretty fast. I don't even raise the top arm to do it. I cannot feed a #2/0 blade down through the piece of wood, through a hole drilled with a #65-#70 bit, with it clamped in the top arm without destroying the blade. I can get it done with the method I describe faster than it take my Fein Vac to automatically shut off once I stop scrolling to change to another hole,,, most times anyway.
The only problem I have with it is if I go back to bottom seeding after doing my method of top feeding for a while, I forget I am bottom feeding, reach down and release the bottom clamp and there goes my blade to the floor.... Then I slap my forehead, reach for my magnet on a stick tool and retrieve my blade and get setup to scroll again.