The main reason Zoro can "tame" Enma is because he used Wado Ichimonji, made by the same person. But let's say the Scabbards also had weapons from this dude, and could "tame" it to the point where they can at least get a few hits in.
Would Big Mom warn against Kinemon using his master's blade?
Would Big Mom warn against Kinemon using his master's blade?
Enma works by sucking the haki of the user. So what Tengu mean by "controlling" is that, you can control your haki usage freely once you get used to it, you will then have no need to worry about Enma sucking your haki excessively. However, this in no way proves Enma will give you extras haki
In the end, all depends on your haki pool, so if Kinemon have had experiences with Kozaburo's sword, he would have made BM warned Kaido in your hypothetical scenario only if he has haki as much as zoro has

