Why would you need to allow modifications the binary und er LGPL? You will need to ship the source of qt and all mods you made to it, but that is it. Or am I missing sth?
Now, I believe Linus Torvalds for example interprets the license differently, and doesn't believe that a company using Linux on an embedded system is obligated to allow their customers to apply a patch to this Linux system (and he certainly doesn't want the manufacturer to be forced to make their proprietary software run on top of the modified Linux, which is why he never wanted the Linux sources to be updated to GPLv3, even if it were feasible to do so).
https://events19.linuxfoundation.org/wp-content/uploads/2017...
> Specifically, I asked him on 2012-05-05:
> > [so], these words in GPLv3: “The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made.” mean that the proprietary software that is not a combined work with the GPLv3'd work must also function?
> Stallman replied on 2012-05-06 with:
> > Absolutely. And I wrote it specifically to do that!
I don't think this has ever been litigated, so we don't know what a judge and jury would find, but I suspect that if they found Bradley Kuhn is right, there may be a GPLv4 that is more explicit about requiring the device to keep functioning as it was, not just as a dev board as he calls it in these slides. And that GPLv4 would apply automatically to lots of GPL software going forward (because of the "or later" clause that many projects are using).
I also think he is explicitly contradicting his earlier article to some extent. He also mentions in that that the whole original purpose of the GPL, as also told by Stallman, was to be able to fox your own printer by patching its code when you find a bug in it. It's clear that "turn the printer into a dev board by blowing a fuse" doesn't achieve this original goal at least - whether it achieves the license terms as written is more debatable.
[0] https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t...