Hello Piwigo enthousiasts

I have the following problem: I would love to migrate my Gallery2 data to Piwigo. (~1000 folders, ~10.000 pictures)
In reading this forum I thought maybe the Menalto2Piwigo plugin might cover my needs.

I placed al my maps and files in "piwigo/galleries" and have done some synchronising (although I'm not sure what that action precisely did).

The Menalto2Piwigo asks some data about gallery 2 tables to migrate the data over to Piwigo. However, to my knowledge Gallery2 doesn't use a database. It stores it's information in text files containe serialized objects. I find this very confusing.
Menalto2Piwigo says "No Menalto Tables Found!". That makes sense, Gallery2 doesn't use Tables, the script should go and look in the textfiles which are next to the pictures files.

Does this mean I have no use from the Menalto2Piwigo?

Very specifically I am left with the following problems.
- In gallery2 each file has 3 instances (next to the original image, there is a 'sized' image, and a 'thumbnail' image). It would be great if the sized and thumbnail image would be removed automatically.
- The map does't get the name from the data in the serialized obect. I am left with the system name of the folder.
- The hierarchy of the folders is ignored. Gallry2 puts all folder next to each other (no hierarchie) and the way the folder are linked in children and parents is stored in the serialized object
- other stuff like comments and rating are also lost. But I'll consider that details.

Thank you in advance for any kind of relevant knowledge.

Best regards,
N