https://portableapps.com/apps/office/libreoffice-portable-still doesn't show up here: https://portableapps.com/apps. Only LibreOffice Portable Fresh does.
This helps us eliminate automated spam accounts
I'm here for like a decade but that Captcha will certainly help.
You'll notice this is the same for any app with multiple builds.
Chrome, Firefox & Inkscape are examples, these each link to the other builds from the main page for the app.
LibreOffice is not different - the main download (Fresh) is available on the main app page, with the secondary download (Still) linked from there.