I have to agree about using parts from post ban mags. But if using a preban ak-74 mag (and its parts) and comparing it to the 5.56 waffle mag parts they look really close. I took some pictures to show how they look side by side.
The Ak-74 spring is on the top and the spring from a 5.56 waffle is on the bottom.
For comparison the -74 follower is on the left and the 5.56 follower on the right. Notice the scribe line on the brown (-74) follower. That is how much would need to be removed to make it work in a 5.56 waffle mag body.
Other than the finish the floorplates are the same and fit on either the ak-74 or the 5.56 waffle mag body.
I'm not saying if it is legal or not to use the ak-74 mag parts in the waffle mag bodies. I am showing the comparison of the two for those that want to know. In other words I'm not saying to do the modifications, that is entirely up to you and no one else.