I'm going to agree and disagree with some of the points raised in here.
Grip angle, grip size, trigger, etc. can absolutely impact shooting. Yes, you should be able to maintain a fair deal of accuracy with any handgun, but not to the same point as with your primary. There is a reason why we train so much with what we use; it develops muscle memory. Before I get the comment, "your muscles don't have a memory, though", the chunk of gray matter between your ears does--and it controls your muscles. Just like we train for an automatic response when confronted with a threat, the specific movements are also trained. When you raise the sights up to your eyes with the 628, the angle of your wrist will differ from that with a 17/19/etc. You will have to consciously correct that. The same is true of the sight height. If the sights are higher on the 629 than they are on the 17, you will have to adjust from one to the other, depending on which you are more versed in.
On the other hand, you can also absolutely train yourself to shoot both of them well. If you train with both of them consistently, you can train yourself to "recognize'' the difference, and automatically compensate. It's the same principle as training with both an AR/AK/etc. and a sidearm. You can train to shoot well with both, but each requires a different set of "memories."
So, OP, instead of training with one or the other; train with both, often, even together.