Hi,
This would need other users to share experience.
There are topics about QT on Jetpack 4:
PySide2 (Qt for python) installation on Jetson Xavier - #5 by Muscle_Oliver
Jetson Nano and Qt5 - #2 by WayneWWW
Pyqt not working on Nano - #4 by coolbot
Please take a look and see if it helps.