I am looking for suggestions on a 938 mag carrier for IWB. I looked at the snag mag, but saw a review that the extended mag does not work with it.
What would be a good option for the extended mag?
Thanks

Any one of the 4+ pockets on your person at any given time.

have you tried to draw a magazine from a pocket fast?

Well yes sir, I have.  And to me, it is like all other things important in the world.  Training is required.  
You will already be reaching with your weak hand in the general direction of your magazine (be it in a holster or pocket) and to make sure you have only the magazine in the pocket is not any harder than putting your wallet in the same pocket everyday.  I prefer the back weak hand pocket.  It is not uncomfortable and easily drawn.

I' mwith Mike

On a pocket pistol like the 938, I would not want stuff in my belt (whole point of a small gun).

change pocket on jeans, crass draw type deal. Or dropped in another pocket.