My one thumb break is designed for the shorter, original thumb safety. That is no problem for the 1911 I use it for.
My other holsters are for the extended safety.
I do not like the idea of relying on grip safety alone when carrying with one in the chamber.
Another thought is to replace the spring in the tube and see if that may stiffen the safety lever.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)