Even though there doesn't seem to be much interest in this topic, I can nonetheless report that some progress has been made since the last answer to this thread. To avoid unnecessary tempering with my smartphone, I decided to write a short and simple routine for my raspberry pi (single-board computer) to manage receiver updates.
Equipped with a small battery, this credit card sized computer is quite handy: Simply plug in the USB-adapter, connect the cable to your receiver, wait for the status light to start flashing, unplug your receiver and that’s it - the raspberry pi automatically restarts the update program, hence this process can be repeated as often as you please.
However, since there still is only a Windows version available, things do not run 100% smooth using WINE and Arch Linux - according to the error log there (as usual) are some issues related to the emulated update program as well as the communication between the USB adapter and WINE. Of course, I could bother to implement this in a Windows virtual machine to get rid of the WINE errors but I am quite certain, that the adapter issues would prevail, which limits the range of applicability of this (maybe) unreliable update procedure to expendable foamies and very cheap fun models, and not the desired target group.