In 8 years of urban/suburban road riding I've only had one instance were I could positively identify tire liner rub as the cause of a tube failure. Normally as the tread wears thin or the casing gets ready to start falling apart there'll be a blowout from a casing cut prompting a tube/tire replacement.
One benefit of the tuffy's is you've also got a make shift tire boot already installed if you've got a casing cut while on the road, replace the tube and shift the tireliner over the rip, that should get you home.