I acquired a trio of button scolys that I've had in my pico tank for two months now. I wanted them for exactly the same reason - they're perfect for small spaces. I have heard they are fairly aggressive so don't put them within touching distance of anything but other button scolys. They aren't miniature or dwarf scolymia, they're just visually similar with an entirely different taxonomy.
They eat well, with the big tentacles very like to classic scolymia. I've got them on the sand bed at around 130 PAR and they're nice and fluffy. I even had one partially eaten by a miscreant sexy shrimp and it regrew -very- quickly. Like, days quickly and the flesh was covering the skeleton. I was very pleasantly surprised and relieved.
- See the chomp taken out of the right bottom. It did it TWICE in two different spots before I said no more. The next pic is within the same day under blues.
The tank is only 3 gallons and this last pic was taken about a week ago. Other than the two spots that were damaged showing a little less vibrancy, the darker one has almost fully recovered.
I got one of each I guess 'common colors' red, green and the dark with orange striping. I love them.