Has anyone come up with a fix for the unworkable right side slide stop/slide release on the M&P 2.0. I own a compact and had read about this problem in reviews before purchase. I just showed this to a LGS on one of their new ones yesterday. They were unaware of the issue. I own a Gun 5 Glock 45 and that one works just fine as designed. Hard to believe that S&W put this gun out knowing that the problem exists.

If you're referring to what I think you're referring to, try removing the slide stop detent on the left side of the slide (new to the 2.0's to prevent the auto-forward experienced w/the 1.0's when a loaded mag was slammed into the mag well).
It's easy to do, there are YouTube videos on how to do it (I removed mine w/a small punch, light hammer & a pair of needle-nose pliers in less than a minute) and it's completely reversible.
HTH...

__________________
His Universe, His rules.

There is no "fix" and this cannot be name as "unworkable".
M2.0 has exact slide STOP... not RELEASE as designed for this model.

That is not what S&W need to be aware of. This lever never meant to be "slide release".

Anyway...
The only thing you can do is workaround.

As Tomac posted - remove the small piece from left slide stop. But this is not everything that has to be done.
Next step is to remove the whole lever and polish it - all the parts working inside the frame.
The final step is to file the piece which catches the slide. Do it gently, otherwise it won't lock the slide back anymore.
Remember to test release functionality WITHOUT mag... once you find it working - wait about 700 - 1000 rounds of live firing. After the whole procedure you will have right slide release working as smooth as on your G45.

At least that worked for my M&P9 M2.0

The easiest fix is the obvious one.

Insert magazine, pull slide slightly rearward and let go.

This works for right or left hand shooters and works on Sigs, Glocks, 1911’s, Berettas, and pretty much any semi automatic pistol ever made.

Here's a thread on this topic where I posted a YouTube video that helped me as a lefty to reduce the force required to operate the slide lock/release from the "proper" side
Picked up an M&P 2.0 Compact today, Lefty ?