While the stiff small thumb safety might make it harder to flip off it also makes it far less likely to be accidentally flipped on during carry or while holstering/unholstering.
I have firearms in various configurations, with and without thumb safety, with and without grip safety, with and without mag disconnect, DAO or SA/DA or SAO. Each has pros and cons in different situations.
So far I have carried with an empty chamber and safety off and with a round in the chamber with safety on. Trying to balance the fact that I have to handle the weapon a number of times in order to get through a day against the chance that I might need to use it.
What about this - chamber a round - put the safety on - holster the weapon (before or after attaching the holster to your belt) - get everything situated, then thumb the safety off - assuming you have a good holster which covers the trigger. Then if needed the safety is off. At the end of the day or when removing the gun from the holster of the holster form the belt, thumb the safety on to make it safer to handle when in a safe location.
Then again there is the keep it simple philosophy where minimizing the parts and steps involved is the way to go. Not that anyone is completely safe anywhere but some level of threat assemesment needs to be done.
I don't feel I need to have my safety off while sitting on my sofa but perhaps I do when inspecting a vacant house.