In addition to this, the OP says a squib kick needs to be scooped and returned, which would take a lot of time off the clock. That just isn't true. If they scoop it at, say, the 30 yard line (not abnormal for a squib kick) and just give themselves up immediately, maybe 0-1 seconds come off the clock and they get better field position than the touchback gave them. The squib really only makes sense if you're trying to prevent a dangerous kick returner from making an explosive play, which is the same thing you accomplish by kicking it out of the end zone. Otherwise you're just counting on whoever scoops the squib to not know the rules.