I didn't actually kill the Demo Lord (not that I was trying to; I'd be savescumming immortality if I was trying). I mostly meant you can stall for ages on the ones preceeding them for long enough to kind of just do everything on the map before fighting them. I got past IX just from doing normal exploration and not putting any thought into beating calamities (that greenhouse is expensive) just out of the fact that Vagrant's Sword allows (and encourages!) doing everything in the map to delay the calamity... and it turns out exploring the entire map actually gives you a lot of stats.
Lemonade stand being a thing you do passively makes sense. The main thing that made it tricky for me was that I only entered the lemonade stand because I wanted to get more Vagrant's Sword delay (this was an exploring run and not one I expected to make grand progress), only got my screaming mandrake late in the run, and didn't know if I'd survive the next calamity or not, so I was out of things to do.