Where i will find information about firmware changelog for example?
The differens between E and USA version are only the allowed frequencies, that the mobile network frequencies are not disabled, and that the database functions have been removed.
The last digit in the firmware version are just for patches and small cosmetic changes in display texts and similar. If the USA version changes to 1.11.xx then Avera needs to decide if it is wortwhile to spend money to make an E version of the firmware. Each time Avera makes a firmware available they loose money. So they usually don't offer updates each time a new US version are released until they are forced to by public demand.
My opinion are that from a technical standpoint it's totally unnecessary to make these E scanner versions. It has to be related to some politics of distribution rights and support rules in EU and similar limitations. Also SDS scanners only selling point are to handle simulcast systems, of which there are non in EU and most of the world outside of America. They serve no purpose as functions and features are exactly the same as in the BCDx36 models that also have a higher performing recevier. It's already a EU model of BCD436 called UBCD3600 so they only needed the BCD536 to be eurolized.
/Ubbe