That would be counterproductive. You practice and qualify with what you carry. To do otherwise would be ridiculous.
don't buy it. unless you are shooting competitively, the small difference in the behavior of different types of ammo is not an issue. especially in a close range weapon like a handgun. i don't doubt that there are departments that spend tax payer money that way. i'm just saying that it's not necessary except maybe in small numbers of marksman type units.
Just imagine. Your in court on the witness stand. Your being grilled by an attorney who's client you shot. All is going well, till the attorney discovers you shot his client with a round you have not trained with....Sound like a petty argument for the attorney? Of course it does, however if you have the experience you say, then you know what an attorney will do to confuse a jury. No agency wants to give an attorney a gift in court. Now I have been retired for almost 14 years. As I recall this is only one of many reasons to train with what you carry.