Speaking for myself, I don’t adjust my grip between the first DA shot and the following SA shot. As far as trigger finger position, I think of shooting a DA/SA pistol as the initial DA pull and then resetting the trigger for each pull afterwards. Even in non-DA pistols the reset point can be different than the initial starting position, so the finger may have to make some adjustments.
Since this is the second time speed has been mentioned, below is a video of Ben Stoeger discussing how he trains with DA/SA. If you watch this and the next video where he is doing live fire you’ll see he’s not adjusting his grip between his first and following shots and he’s still quite fast.
https://youtu.be/VYfOM4up4dU?si=hfiIzTKwJqtE_QWM
https://youtu.be/nmesYY4W1wE?si=y3KZLD9F6VsG7QSd
Again the Shadow 2 is pretty common in USPSA and if speed with DA/SA was a large hurdle it wouldn’t be as popular as it is. Now I’m not saying everyone, including myself, is as fast as say Stoeger, but the idea that the shot process needs to be completely reset between DA and SA to the point where it’s a significant hindrance is shown not to be the case for many people that put the time into this. As I said earlier, if a person doesn’t want to put the time into getting to that level, that’s their call. I think a fair argument against DA/SA is that some people find it takes longer to build the same proficiency with it as other trigger systems.