I think overclocking in portable mode would only be feasible if you have your Switch connected to a power outlet, otherwise the battery power draw is just too high. But that can certainly be a viable option if you're for example playing on a train or plane where power sockets are often available, or if you just want to play at home without a TV. In these cases the temperature of the unit as well as the fan noise might still cause problems though.
In general though I don't see any reason why the Switch shouldn't be able to use all the available power if used in tabletop mode while connected to a power outlet and I'm actually a bit surprised that Nintendo didn't think of this option. Technically it really shouldn't be a problem for them to introduce a full power tabletop mode that simply outputs the TV image to the internal display, basically letting the Switch think it is docked and connected to a 720p TV. But I guess they don't think it's worth it as it could lead to potential problems when people don't provide enough airflow or stuff like that.
In general though I don't see any reason why the Switch shouldn't be able to use all the available power if used in tabletop mode while connected to a power outlet and I'm actually a bit surprised that Nintendo didn't think of this option. Technically it really shouldn't be a problem for them to introduce a full power tabletop mode that simply outputs the TV image to the internal display, basically letting the Switch think it is docked and connected to a 720p TV. But I guess they don't think it's worth it as it could lead to potential problems when people don't provide enough airflow or stuff like that.











