Here is a very recent exchange between a GNU/Linux user with an HP printer and someone at HPLIP by the name of srikanth, who concludes the thread very politely, but firmly, by saying
Sorry to inform you that as of now there is no plan of providing the partial support for manual duplexing feature. ... Sorry for the inconvenience caused. (emphasis added)
With apologies to sirikanth, inconvenience, my foot! Since I know of no alternative to hplip, perhaps it might be more helpful to say, "whenever LinuxMint users are in the middle of a task that requires doing double-sided printing, simply exit your program and operating system, boot into MS Windows, find the files and print them, then reboot, to continue working in Mint ... "
Is this too severe, or am I missing the point? This is an inconvenience? Yes, I'm aware even that wouldn't work, since Microsoft's operating systems can't 'see' Ext4 files, without installing a special utility ... does that make the situation any better, or is it now even worse?
Is there anyone here, at LinuxMint, who agrees this situation unacceptable to LinuxMint users, and is able to appeal to some 'higher authority' over there, at hplip?
This refers to hplip v_ 3.12.6