This is just my perspective -
I see that most age in glass -
Yes you must be careful when handling any glass container - the person trying to clean a carboy in a porcelain tub - BAD IDEA !!
This is one of the many reasons I came up with the Allinonewinepump - so there is no lifting of any full carboys. I also recommend using crates to move the carboys safely, protects the bottom and sides and easier to carry.
When cleaning add 1 gallon of cleaner or sanitizer and use the drill operated carboy cleaner - this way you are only lifting 1 gallon of water while dumping the carboy, much safer.
Just make sure that there is no big water temperature change as that is one of the first things that will cause stress cracks.
I have alot of carboys - I broke 1 due to extreme temperature change - it just cracked , luckily it was empty.
I did come up with an accessory for the Allinonewinepump to now transfer into plastic (PET ) carboys under vacuum - no lifting of any full carboys