[applesmasher]

Picture a rifle, such as a regular EBR, configured a little differently.

Stock, action and barrel? Pretty normal, but turn the trigger group outward along with a pistol grip or similar, about 60 degrees as if accomodating someone who usually cants their rifle when shooting.

Now on the forearm, add another pistol grip, canted out 60 degrees the other way.

Upsides:

More comfortable/ergonomically correct arm/hand/wrist positions.
In prone, it can act as a poor man's bipod of convenience.
Not in prone, the combination of the two grips affords an excellent three dimensional steadying force - especially in combination with the stock.
Either grip can act as a convenient monopod against a wall, tree trunk or whatever else is around.

Downsides:

.... slightly bulkier?

 

[applesmasher]

It occurs to me that the easiest approximation of this would be your EBR of choice, with quad rail (or similar) furniture up front, a pistol grip attached to the side thereof so that the trigger hand and off hand are at right angles, and then turning the stock so that it is at 45 degrees with respect to each other them.

If you want a wider angle between hands, turn the forearm and the stock until you experience joy.