Thanks for the interest! For some OEM ECU's, I've found that a hard TPS reset is needed to reset the throttle position to zero. Most claim that all you need is to scan/clear for codes, as it does a soft reset, and/or disconnect the battery over night, but in some cases, you can still see some mild idle fluttering as the throttle blade isn't in exactly the same spot as the factory TB. I threw one on my wifes 2015, and saw no drivability issues with a battery disconnect, but we also had a police cruiser as a test car that ran/drove/idled normal most of the time, but was found to run alot better with a hard reset. this is true of ANY throttle body change on a late model car, not just our throttle body.
All that being said...if you're just replacing a stock TB, on a stock engine, with no other upgrades, then a TB isn't going to yield much. To the point of, I wouldn't mess with a fine running 2021 if you're not going to be doing at least full bolt ons. Pretty sure the 6.4's were 80mm TB's in that year, but much like throwing a 850 Double pumper on a stock 360...the engine wont benefit from the extra air. Now go from 80MM to a 92MM on something with a nice cam...yes, it'll be noticeable.