Ha, ha,, ha, I have owned a DeWalt, Excalubur, Seyco and Hegner and I could/can not top feed on any of them... I need a video of someone feeding a 2/0 straight or spiral, or a 3/0 spiral blade, down through a #70 drilled hole in fret work.. I do it by removing the blade from both top and bottom clamps.... hand feeding the blade through the little hole in the wood and hole in the table, then clamping the blade in both clamps... Is that how it is done? Is that called "top feeding".
I can't answer your question,,, I can not top feed on any scroll saw (for my kind of scrolling)... I am too much of a clotz I guess.