LDK linear 64 palms seems to be primarily based on Yue Shi Ba Fan Shou 64 set. LDK version appears to be have been modified to use some Liu He Men / Bagua / Xing Yi movements though.
Liu He Men is mainly long fist. After you learn the basic forms, there is form with an emphasis on agility that has some twisting movements called Qing Long (green dragon). Circle walking even appears in a very short section. I can't find a decent demonstration of it online though. Either way, if it had an influence on Baguazhang it would have been pretty minor. While there might be some outside influences to Baguazhang in regards to certain key movements and applications, I think the core bio-mechanical part of Baguazhang (as in the bit that makes it Baguazhang as opposed to something else) started with DHC.