On your '94 (and later years) the PCM will actually cut ignition/fuel briefly to ease the transition, making shifting a little easier on the trans and driveline. It's completely imperceptible.
The PCM will set an error code if it detects a difference in engine RPM and output shaft speed beyond a reasonable tolerance. Since the torque converter is supposed to allow slip during acceleration, so the PCM might not lock a code until the trans slips at cruise speeds and loads.
As advised, an upgrade kit will typically address some issues common with a given transmission.
If it isn't too late, you might want to ask the rebuilder about removing the 3-4 clutch pack return spring cages, sizing the front end clutch spacer for the low end of clearance, and making sure it has at least a 6-disc clutch and steel set (some came with 5 and an extra thick spacer).
The black caged steel return springs in question are in the middle of the photo:
A modified TCC boost valve is a good idea, either by replacing the valve spool or modifying it on a grinder.
A new separator plate is about the best $20 you'll ever spend inside a trans.