From software 2.38.0 or higher, the option is added to disable the Blind transfer option in the DECT handsets.
This can be activated via auto-provisioning and is created for VoIP platforms that do not support Blind Transfer.
0 = Disabled
1 = Enabled (Default)
Example:
<?xml version="1.0" encoding="UTF-8"?><settings version="1.0" productID="e2">
<param name="SipProvider.0.BlindTransfer" value="0"/>
</settings>