FYI...
The default tiddlywiki (zoom-on) viewport meta tag:
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
To turn zoom-off Quine replaces the in-memory html with viewport meta tag:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0" />
To turn zoom-on Quine restores the default viewport meta tag.
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
Quine saves your zoom-on/zoom-off preference between sessions - so when you open a wiki it will set the viewport meta tag based on your zoom-on/zoom-off setting in the toolbar (...) menu.
Chris.