@youbu, I happen to be building a major SEO addon for Xenforo 2, which is aimed to take the place of other unmaintained solutions. It happens to draw inspiration from Yoast and similar plugins (I've used them for many years so a lot of experience there). If you're interested, let me know as beta release will only go out to 10-20 users. It has many functions similar to what you're looking for including custom meta title and description with live Google Snippet Preview for all Xenforo sections, even third-party addons:
View attachment 219713
As for your question, you can't set custom meta info for individual categories without an addon, but since you said you're not using descriptions for categories, you could set them as your meta descriptions and then simply hide the on-page version by adding this to extra.less:
Less:
[data-template="category_view"] .p-description {
display: none;
}
And here for forum_view (thread list):
Less:
[data-template="forum_view"] .p-description {
display: none;
}
As for the forum title, you can show your board title on the page as normal, but show a custom title in the head tags for Google:
Template: forum_list
Find:
HTML:
<xf:h1>{$xf.options.boardTitle}</xf:h1>
Replace with:
HTML:
<xf:title>Enter a custom meta title to display in the head</xf:title>
<xf:h1>{$xf.options.boardTitle}</xf:h1>
The board meta description set in Options does not appear on your forum. It's designed only to show in the head meta tags, so you can customize this for Google as needed.
Let me know if these work for you,