Laser head hitting the sides

As I explained, this is only party correct. If you have one switch per axis, you have hard limit protection in two directions, like -X and -Y, usually (of course, not the other two). And since you can damage your limit switches if hard limits are not enabled, you should have that always enabled if you have at least one switch somewhere. Because if you don’t and rely solely on soft limits, you will break your switches if the laser head loses position and tries to get past the switches (I already did that).
Of course, it does not make sense to only have hard limits enabled with one switch per axis, because it will only protect one side of the mechanics. You need to use soft limits as well then.