Please remember, we are in a war on preferences: bug 52807.
As a workaround, you can change the expiry date of the cookie which the tux=0 parameter sets: just search "tux" in the cookies of your browser (ctrl+I in Firefox) and do whatever needed to edit the expiry (an add-on may be needed, e.g. https://addons.mozilla.org/it/firefox/addon/cookies-manager-plus/ ).

(In reply to comment #1)

Please remember, we are in a war on preferences: bug 52807.
As a workaround, you can change the expiry date of the cookie which the tux=0
parameter sets: just search "tux" in the cookies of your browser (ctrl+I in
Firefox) and do whatever needed to edit the expiry (an add-on may be needed,
e.g. https://addons.mozilla.org/it/firefox/addon/cookies-manager-plus/ ).

Problem is that I use several browsers and devices and it's absolutely impossible to manage cookies in many (I think in the majority of) mobile browsers.

(In reply to comment #2)

it's absolutely
impossible to manage cookies in many (I think in the majority of) mobile
browsers.

I'm not going to investigate all browsers of all OS of the world but some managing is possible, hence I suggest to search a bit: https://addons.mozilla.org/it/android/search/?q=cookies

I'm going to mark this as WONTFIX, as we would not accept patch for this. The old UI is explicitly not supported.

Unfortunately nobody seems to working on our mobile apps currently, which could provide some help for you.

Sorry but I insist. Why are you ignoring users' need? Why I must be not able to edit via mobile because you don't want it? TUX is ugly and very low functional in compare with tux=0 - why on Earth are you imposing tux=1? I'm not able to work in tux=0 because of things I listed in the description and it's absolutely impossible to work there via mobile. Mobile apps are not the solution because they usually are just for 2 platforms (android & ios) which I don't use.

Shall be "I'm not able to work in tux=1 sure". I was typing fastly.

No opinion on last two comments, I'm just making the summary a bit more generic/to the point.

In the end maintainers decide which patches get in, and if Niklas says that there are no human resources to support two interfaces at the same time this means de facto WONTFIX. If you would like to challenge general priorities of development teams or even of the Foundation, please feel free to do so, but this would be too high level for this bug report itself.
Thanks for your understanding.