I just have to imagine that this idea will go kaput once "apostates" start engaging JWs in discussions at these lit stands.
There aren't that many "apostates" who care enough about JWs to engage them in discussions. It is exceedingly rare that a typical JW out door-knocking on a Saturday morning will happen to run into one.
But if there is just one "apostate" in a congregation's territory, and if he/she is the least bit clever, he/she can go to the "Wal-Mart" stand, feign "genuine interest", and present some seriously uncomfortable points for the JW.
In the rare case that a JW finds an "apostate's" house, the JW can scurry away.
But if a JW has a 2 or 3 hour "shift" at the Wal-Mart stand, where's he going to run to?
The potential for the JWs to be embarrassed at these portable lit stands is enormous. I honestly don't see this idea lasting more than a few years.