I can't paste images into the body anymore, so here's a link to one example: https://piefed.zip/post/1645895#comment_6124522 (user “makeshif*”).

This appears twice in the HTML code:

        <span class="fe fe-warning red" title="Very low reputation. Beware."> </span>  
            <span class="fe fe-warning red" title="Very low reputation. Beware!"> </span>  

I just realize it's “… Beware.” and “… Beware!”. Two different texts.

It's so unimportant, but I couldn't let it go. I searched the source, and the following code is written this way in 4 different files:

        {% if user.reputation < -12 -%}  
            <span class="fe fe-warning red" title="{{ _('Very low reputation. Beware.') }}"> </span>  
            <span class="fe fe-warning red" title="{{ _('Very low reputation. Beware!') }}"> </span>  
        {% elif user.reputation < -3 -%}  
            <span class="fe fe-warning orangered" title="{{ _('Low reputation.') }}"> </span>  
        {% endif -%}  

So the answer is “especially problematic”. Probably twice because red and orangered aren't distinct enough.

Hardcore DRY fighters will see this as a bug because it's repeated in multiple files. But templates don't get more readable if you never repeat yourself.

Yes it's intentional.

Jinja templates get really slow if you have many levels of {% include %} inside loops, like when showing many comments or posts at once.