Hi Alexander,
1.Which version to use for testing, please see there are two options there:
image.jpg (101.9 KB) ?
2.Is there also professional tool , not free?
3.How do you recommended to make the test?
For example :…... For example :QA will convert from Shapefile to GeoJson using...my Gis Converter tool and later use the QGIS to converted it back...