Nothing that I'm aware of, there are gen chrono watches that use valjoux based movements and so reps of those watches can use a valjoux movement without the secs mod (safe). There are gen chrono watches that don't use valjoux based movements (all the good ones) and the reps of those are flawed because they end up being too thick to accommodate the always thicker a7753/50 movements, and have the mod to the secs position making them unstable. The only way to use the right movement for your watch is to mod the case itself and lower the crown height, there's no plug and play option. That's why the zenith daytonas are popular builds for people because they want to use a movement that's not a ticking time bomb. Lots of other watches like some Pam's and many others use swiss 7750/53 movements so if you bought a rep of one of those and opted for the Swiss movement or plopped one in yourself, everything would be good. Long rant sorry! Basically I really don't think that watches with those movements should be purchased at all, they are flawed, and will one day stop working, it's the rep factory's answer to all the diff chrono config's the gen company's have produced, and it sucks. There's a reason why the manufacturers of the high end non valjoux chrono movements have purposely placed their sec's subdial in a diff location than a run of the mill 7750/53