I've got a sequential manualised-auto with a stage II shift kit. Using MV Automatic's electronic shift controller you can disable the auto ECU to make it behave similar to a manual valve body. As the name implies having a manual valve body requires it to be driven like a manual just without a clutch so, you wouldn't leave off from the lights in 4th
There's no O/D & kick down function so, now O/D button off=3rd & O/D on=4th...think I got that right as, I use a ratchet shifter. NB: If you have the O/D on (4th) still engaged & then shift gears the trans will flare & can shock the trans when you correct it back into gear .
With med-high loads the shifts between gears are instantaneous & crisp but, off throttle & low loads gear changes can sometimes be a bit jerky. Also, for me going down from 4th->3rd the engine brake doesn't engage & not sure if this is the same with a 4speed manual valve body. But, yes when you down shift & plant it, it will haul, as well as, chirp the wheels even in 3rd .