Less than lethal ammo is designed for LE agencies to control rioters and for corrections officers to control rowdy prisoners.
It is NOT designed to protect you from someone who has broken into your house with the intent to kill or rape you and your family.
If "over penetration" is a concern to you, use #3 or #4 buck shot.
Another option is to use reduced recoil 00 to manage penetration.
The biggest reason that people use shotguns for HD is the fact that you get maximum effectiveness with minimum overpenetration.
The last thing you should be concerned with is what a "good guy" the burglar in your house is.
I am a father and a husband. My primary job in life is to provide for and protect my family. I damn sure am not going to be wondering if the guy who just broke into my house is a "good guy".
As you stand there trying to ascertain how good the guy who broke into your house is, he will be thrusting his buck knife into your abdomen.
Bottom line, forget about loading your shotgun with rubber pellets and load it with something like buckshot, that will preserve and protect you and your families life.