Not sure I ever seen a grid on a beauty dish.
Lots of choices from many brands of octa's, etc with grids.
Grids are widely available for rigid beauty dishes. Most makers offer beauty dishes ... and Mola makes a wide range of sizes from their 22" Demi, to the giant 43.5" Mantti ... all of which can be used on most any light with the proper mount.
Of interest may be Honey Grids, a company that makes rigid, snap-in grids for almost any make of beauty dish ... or even make a custom one if you wish:
http://www.honeycombgrids.com/
The advantage of rigid grids like Honeygrids makes is that they can be had from a narrow light spread control of 10º to a wider 45º, and ordered in either the typical black or more flattering white.
The objective of a beauty dish is precise control of the light with less spill onto surroundings, and perfectly round catch lights.
These soft beauty dishes seem to be gaining popularity, especially for mobile applications. I have not used one yet, and would love to hear about user's experiences. I currently use the Elinchrom Rotalux 27" Deep Octa with a Profoto mount for my lights. The Rotalux's modifiers are very mobile because they set up and break down super easy and fold-up like an umbrella for transport. They can be fitted with a silver, white or gold bounce deflector inside like a beauty dish, and come with those as part of the set. So, it'd be interesting to hear how these soft beauty dishes differ.
- Marc