TCP_NOTSENT_LOWAT on FreeBSD?

[Sebastian Huber]

Hello,

I use the mDNSResponder from Apple in embedded devices on top of the 
FreeBSD network stack. I tried to update from v878.270.2 to v1096.40.7:

https://opensource.apple.com/tarballs/mDNSResponder/

However, the Linux/macOS specific feature TCP_NOTSENT_LOWAT is now used 
in the new version:

https://lwn.net/Articles/560082/

Is there something similar available on FreeBSD?