The current screenshots of the Sigelei showed it not using a Yihi chip, but rather the same type of chip as found in the new Snow Wolf 200W - basically, another DNA 40 type device (but not a direct clone.)
Now maybe this new DNA40-like chip in the Snow Wolf and Sigelei is actually made by Yihi? But I doubt it, because around the time of the Snow Wolf 200's announcement, Yihi put out an announcement denying they had anything to do with it (they denied they were involved in any 200W mods being released at this time, or something like that.)
You can see the Sigelei is the same layout:
Sigelei 75W
Snow Wolf 200W: