As someone who has more experience than I care to quantify regarding RAM-starved, swap-abundant systems: no. Well... OK, a subjective measurement on the "death

As someone who has more experience than I care to quantify regarding RAM-starved, swap-abundant systems: no. Well... OK, a subjective measurement on the "death by how many thousand cuts"-scale would be somewhere between 10,000 and 1,000,000 cuts, IMO, depending on what you're trying to do. You'll also rapidly exhaust the SD card's flash lifetime, and all the spare capacity... which will make the SD return read errors, nicely corrupting the contents of RAM. You can verify the slowdown/lag/pain factor easily enough: boot Linux on any PC with `mem=2G`, attach an SD card you don't mind nuking :), and go nuts.