I carried a 1911 IWB for years, and regardless of holster make or type, I would find the safety off at the end of the day on a pretty regular basis. 99% of my guns were stock Colts, with the standard safety too.
If you think about it, its really a non issue if its in a holster. Generally the grip safeties work (Id check yours anyway, Ive had a number that didnt, including my last Kimber), which adds another level of safety, and the trigger is covered by the holster anyway.
“The enemy is anybody who's going to get you killed, no matter which side he is on.”
― Joseph Heller, Catch-22