for anyone wondering where they can watch this special, it was in fact released within the anime
it is episode 5.5 on crunchyroll and other streaming services that have the show.
The plot main plot follows a man trying to quite literally win the approval of the father of the woman he loves. The story is pretty barebones. It does what it has to do and it's executed really well. Basically the bread and butter of Shiguang Dailiren at this point is telling short, succinct, and emotionally satisfying stories. If you liked the previous episodes you won't be disappointed here.
The art and sound are consistent with the mainline stories. Nothing much to say. However due to the martial arts nature of the special there are quite a few entertaining fights that look and feel pretty good.
The characterisation is pretty on point. The episode is short, and most of it is the two protagonists of the show essentially reliving key points of the main guy's life, exploring his motivations and intense determination. The character arcs are all resolved satisfyingly just like the plot.
Overall, I really enjoyed this episode. It came at a time when the main show was trying to be serious and intense, so the special served as a kind of return to the first 2/3 episodes which were also just short, simple, and satisfying stories.