The only penalty is using up your flash's write cycles; but of course, this works to Apple's favor because it means you'll need to replace this thing sooner when the flash dies. Best part? You can't easily replace the flash because it's soldered to the board.... and the amount of people that could do this repair properly is close to non-existent.

Try running a browser and adobe creative suite along with a darktable/lighttable. That kind of photography workflow also fills up the tiny available storage really fast so the macs end up being unwieldly octopuses of fragile USB/thunderbolt devices. I don't do it myself, but I do do tech support for them when they go wrong. And usually it's because they run out of the paltry 8GB of ram.