Kitchen sink drain occasionally clogs at junction 40 feet downstream from disposal
If you want to find out whether there is anything special about the point where the clogs seem to happen, hire a plumber with the capability to run a special viewing camera through the drain.  If a repair was judged to be necessary it is possible that it could be done by tunneling under the slab rather than breaking a hole in the slab.

But the easiest thing to do would be to dispense with the disposer. We did away with our disposer more than 25 years ago. We collect food scraps in a bag in a can (10 in diameter x 10 inch deep) on the counter top and put them in the garbage. Many people do this nowadays. The waste water treatment authorities discourage the use of disposers.