Let’s shift this to ‘How to’ as it will take some creativity.
And then- what happens if you turn php ‘on’ in the main template and inside the weblog tag, set:
{exp:weblog:entries}
<?php $id = '{entry_id}'; ?>
{/exp:weblog:entries}
{embed="site/comment" id="<?php $id; ?>"}
Then create a site/comment template with just the comment form on it- and hard code the entry_id parameter- using the embed variable {embed:id}
Note sure this will work- it’s going to depend on how parse order shakes out. Would need to be parsed on output- and I’m not dead sure it will be defined for the embed. But- that’s the first thing to try. Might work nesting the form inside the weblog tag- where the {entry_id} variable would be available. But nesting like that tends to lead to variable conflicts- so that’s problematic as well.
Worst case scenario, do a query to get the latest entry id. But basically? You need that entry_id so you can hard code it in the form parameter.
Make sense?