Does the ECU checksum correction work on modified maps where the checksum wasnt corrected by any software beforehand ?
Anyone know ?

The checksum correction should work on modified maps even if the checksum was not corrected with some other software. The biggest problem is the tool itself. The quality of it. With clone tools you always gamble with your cars ECU.
The most funny thing is that even original tools can sometimes block the ECU(voltage spikes, bad connection, user negligence), so every flash you make is risk that you take.

Thanks.
I have upload loads of times with various remaps by pro companies.
Appears rock solid with win7 and my laptop.
Just scared of locking the ecu if the checksum feature doesnt work.

I've had some success with ME1.5.5 reading , but not tried writing yet until I get a spare ecu and benchtop setup.

Had tried to read from Porsche ecu as well but that needs to be hardware modifed into a boot mode

i have both galletto clone and original ,but for some reason the clone works better :D

Galletto clone does work well -- i fnd the same result.