Reinforcements for whole floor removal
What I also do when chiseling the pieces apart is when I hammer in the scraper or separator in between the sheets to seperate the spot welds, if it comes to a dead stop, sometimes theres not enough ground out to seperate the weld, or try positioning the scraper coming in from the other direction. Sometimes you have to grind a little more. I have a custom separator I made from a piece of .050" stainless steel 1&1/4" wide with a sharpened edge, and handles made of 2 pieces of 1/8" thick plate aluminum bolted to it for smacking with a hammer. I also have a piece of .063" stainless about 2&1/2" wide and 2 foot long with a sharpened edge for separating floor pans from framerails. It too has a smackable end on it.
Now I do use spot weld cutters in certain circumstances since they also have their place doing stuff like this, like if I am removing a sheetmetal part that I will then reinstall. The RH inner fender on my sons cuda is a solid piece, however I will carefully remove it so I can sandblast both front framerails , and upper control arm attach points on the framerails then apply epoxy primer. The LH inner fender I chopped it out destroying it in the process because it was junk and I was replacing it anyways. With the spotweld cutters leaving raised "nubs" It helps me to center the RH inner fender when i reinstall it afterwards.
The reason I dont care for spot weld cutters for everything is you can drill too deep with them and start cutting into or through the metal your trying to keep if not careful.