I normally don’t open carry. But I have ran into the store and some other places openly. I would think that a good retention system whether it’s a physical strap or just a well-adjusted holster making it difficult to be drawn by someone other than yourself would be a good idea. I prefer leather holsters for comfort but I also love my Alien Gear. I generally try to wear an over shirt even if it’s short sleeve in the warmer weather to conceal. The Alien Gear holster I use has 4 tensioning screws throughout the holster, it would be very difficult for someone to grab from the wrong angle. For the woods, I wear a drop down leg holster which does have a strap over the backstrap.
I normally leave the top couple of buttons unbuttoned for quick access, I have on an undershirt as to not look like someone from That 70s Show LOL. A couple of the shirts I have are five eleven tactical, they use snaps instead of buttons. Then you could quickly tear open and not damage the shirt. Granted, it is not a speed holster, but I can draw almost just as fast from the shoulder rig as from the hip. With a little practice, as you’re reaching and gripping the gun, you’re breaking the thumb strap loose at the same time. I would highly recommend it as one form of carry, but everyone has their own feelings on it and preferences.
The variety of need and clothes makes for alot of fine tuning for any brand of holster. It may make “open carry” more awkward until mastery from lots of practice. Do you have friends to shoot with or a range that has some test holsters. Ranges that perform training may have some to test