I just tried etching some small glass tiles, using settings that I read about here
The pattern in the etch is interesting. There were some bubbles in the dish soap, but they weren’t uniform, so I am not sure of the cause. Perhaps as the dish soap vaporizes, it causes this effect.
Settings: Speed 360, Full Power (GF standard), LPI 225, dot density.
The glass tiles are available on Amazon: glass tiles