Kontact

The OP appeared to be using the word ledge to refer to the raised beadlock, not the raised area that the bead seats over - which I called a "shelf". So the three sections you posted miss one that is between the first and second - having a center channel but not beadlock lip.

masi61

I run 25mm tubeless Panaracer Agilest TLR front and Agilest Duro TLR rear on my Velocity Quill tubeless rims. These are taped with 2 layers of tubeless tape that is like 21 or 22mm width. The square bead internally has no extra “ledge” but the standard square bead seat combined with the square tire bead of the Panaracer TLR’s is pretty secure when mounted under high pressure with my Airshot air canister pumped up to about 140 psi. Laying down 2 perfect layers of tubeless tape devoid of air bubbles is a practice makes perfect type proposition. Sometimes you get it wrong and air loss is unacceptable worst case requiring redoing the tape job. But by instilling latex sealant after the initial bead shelf “pop, pop, Pop” procedure, small air leaks usually seal up when you go ride the bike right away.
My other road bike has tubeless Hutchinson 23 front and 28mm rear tires with DT Swiss R460 rims. Same story here, 2 layers of tubeless tape a few millimeters wider than the tubeless rim interior width is a best practice. The Secteur 28 rear is the only one that might require deflation before removing the wheel. I will pull the presta cores out for different reasons when doing wheel and tire preventative maintenance and sometimes due to rapid deflation, one of the beads will dismount. This usually won’t ruin your day though if you mount your tires with the valve cores out using the little high flow Adapter that comes in the box with the Airshot. If you have your presta core premounted in your core removal tool you can time it to where you let out the initial high pressure blast, push some sealant in with a Park Tools sealant syringe then reinsert the presta core in a workmanlike manner. Again, once re-inflated with the core in I usually overinflate for the first ride and the recheck pressures at the conclusion of the ride.