I've tried numerous gunstocks, but always found them other too heavy, or too hard to use.  “Cup” style controller mounts and magnetic ones always felt too slow, or difficult to re-engage, so I made this one for myself.  This version leaves the dominant hand controller mounted at all times, while the offhand is simply pushed against the front of the stock with the finger wrapped around the gunstock the press it against the grab button.  It is  quick to engage and disengage in combat, and easily allows inventory management, climbing ladders, throwing grenades, etc.

Has adjustable front and rear lengths and cheek rest height.

I recommend installing the touch controller front the bottom and rotating into place before securing it with the included latch.

You will need a 1/2" piece of angle aluminum, 1/20" thick.  Available at Home Depot (Item #204273980).  This will need to be cut into lengths as desired and the cut edges will need to be smoothed out.  I used an angle grinder with a cut off disk for both tasks.

You will also need a total of (8) M3 sized bolts ranging from 15-25 mm in length.  You may substitute other bolts, but will need to provide alternate thumbscrews if you don't use M3.