XF 2.1 prefix_id in new thread's URL query string?

[rebelde]

This thread showed how to set the prefix and title in a link to a [new thread] in XF 1:

XF 1.5 - Query String parameters on new thread to set title/message template

Are there any query string parameters to pre-set the title and/or message when creating a new thread? I want to add a small link below each post that essentially allows the user to "create new child thread" based on the existing post. If clicked, it makes a separate thread in a designated...

xenforo.com

Example URL:

https://xenforo.com/community/forums/xenforo-questions-and-support.25/post-thread?title=Yes+you+can+;)&prefix_id=22

The title still gets set, but the prefix does not. Is there a way in XF 2.1?

(I can write some JS if necessary, sure.)

Thanks!