Tildes.net is still very young and future updates might cause this userscript to stop working.
Please tell me if you find something is broken. The chances of me getting things fixed are greatly improved, if you include your browser version and a copy of any error messages in the console.
Userscript has been tested with Firefox Developer Edition 61.
I've been told that it doesn't work on WaterFox, due to CSP. Unfortunately, there seems to be nothing that can be done about this. CSP should not interfere with extensions by design, yet in this case it does.
A "bleeding edge" version of this userscript is available as a gist. I will update this greasyfork version less often; consider it a "stable" version.