Found new things to get the updi upload working,
To get it working, i had to update avrdude inside ".platformio\packages\tool-avrdude-megaavr" to version 7.x
This way , i got access to "upload_protocol = serialupdi" , used it to upload my little test program to the chip , then as it wasn’t working, hit the “set fuses” button and voila, it worked .
Next upload did not need the “set fuses” action again, here is my working platformio.ini
and my updi programmer is a simple diy ch340
[env]
platform = atmelmegaavr
board = AVR64DA32
framework = arduino
board_build.f_cpu = 24000000L
[env:serial_updi]
upload_protocol = serialupdi
upload_flags = -e
-v