@rooty
I managed to do it to expand the system partition from 2GB to 6GB. Went into recovery mode UBports:
simbion@simbion:~/1$ adb devices
simbion@simbion:~/1$ adb pull /data/system.img
simbion@simbion:~/1$ dd if=/dev/null of=system.img bs=1M seek=6144 count=0
simbion@simbion:~/1$ e2fsck -p system.img
simbion@simbion:~/1$ resize2fs system.img
simbion@simbion:~/1$ adb push system.img /data
The process is not fast. After that, I have all the updates and applications began to be installed. It would be nice if did it in UBports when you install to select how much you need to under system.