I know that the legitimate ones that do “Up Shperchin” are yerushalmi women who have been taught the proper way by
great-great- grandmother passed down mother to daughter, for many generations. There was a famous name whom was known and popular in yerushalayim, I know ehliche people who sent their children to this particular family (woman) but that was over almost 50 years ago, it was a known by practice by the yershalmi’s and if it was any issur of imitating the goyim it would’ve been Assured way back and wouldnt of made it this far.
Though most people who do it today, who cannot trace it back many generations in their family..you must know, like most mekubalim today….(ahem!)
Also most practices the goyim actually took from us, just as most
of christianity, muslims, took their monotheism, customs, (warped versions) and concepts from us.
I heard the tzemach tzedek has a teshuva that it can be done on shabbos for a choleh Mesukan (pikuach nefesh) for it is baduk Umenusa that it helps.
(I can’t verify the that this teshuvha legitimately exists.)