From my understanding, Chan Yik Yan knew of a sword form of LHBF. He wanted to teach my teacher's teacher who refused because Yik Yan was in very poor health (I think after getting hit by a motorbike). Unfortunately, Yik Yan died before teaching it.
I do not know if it was taught to someone else before my teacher's teacher.
Also, I saw one of Choi Wai Lun's students in a video doing a sword form as well. However, I don't know if that's LHBF sword or from one of the other things that Choi teaches or the student learnt from somewhere else.
LHBF has knife (dao) form, but it's not really LHBF's. It's a modification of the trans-style sword form known as Yan Qing Dan Dao. The Praying Mantis version of it was part of my training.
There was another LHBF guy from Hong Kong (I think it was Liang Zipeng who I think lives in Taiwan now) who supposedly was taught a sword from from Hwa Yu (the mountain where LHBF is supposed to have originated) by a Daoist priest/monk.
Personally, I think LHBF does not lend itself well to sword. Might as well go with Taiji sword forms.
The reason I say that is if LHBF philosophy were applied to swordsmanship, it would look really boring. You don't find acrobatics in LHBF. Plus it wouldn't really add anything to the sword that Taiji sword forms don't possess already.
LHBF is more suited for empty handed techniques and any weapon used would really just be treating the wrist as a second elbow. Or alternatively it would be treated as an extra big hand: ie, you change it just like you would with Japanese action figures for different weapons or hand shapes. With LHBF philosophy, you would be very likely to cause a parry and use the resistance as a chance to tie up the opponents hand: ie, occupy it like you would in warfare by keeping opposing forces occupied defending their supply line while you also attack their command.
