I dug out my digital inclinometer, zeroed it to my generally flat garage floor and placed it on my gas cap to measure the actual angle from vertical on the sidestand.
Wheel to left: 10.9??
Wheel to right: 12.3??
So, turning to the RIGHT should actually be more stable on level ground.
I disagree because stability is not wholly determined by lean angle. Stability is also determined by how far apart the bike's supports are.
With the front wheel turned left (toward the sidestand), the front tire contact patch moves to the right, so the three points that support the machine (front tire contact patch, rear tire contact patch, sidestand foot) are further apart than if the front tire is turned right. With the tire pointed right, the front contact patch moves left, towards the sidestand. The triangle of support becomes narrower, and the bike is less stable side-to-side compared to a bike resting on a wider triangle.
In the real world, I think the answer depends on the interaction of several factors (levelness of ground, lean angle, whether the front wheel is turned right or left), not just just on front wheel direction.