This is an interesting idea. I think there are decent points both for and against this idea. Like you said, it would be a cool way to have a more blatant lightsaber duel since there really isn’t a traditional one in this film.
Lightsabers aren’t meant to be a mass-produced thing, but the lightsabers Imperial Inquistors used, like the one’s used in Rebels, were manufactured and not originally made by each Inquisitor, so it wouldn’t be totally unheard of.
On the other hand, the original Imperial Royal Guard used vibro-based weapons, so the weapons they use in-film are inline with that. I do think the Legends “Shadow Royal Guard” had lightsaber pikes, though. Also, the Imperial Knights from the Star Wars: Legacy comic series were styled off of the Royal Guard, and they used silver lightsaber, which also would be pretty cool to see.
Anyway, I think it is a pretty cool idea to just set it apart from other TLJ edits. I imagine it was/is a lot of work though: I think some of the weapons’ blades are wider than a traditional lightsaber, and some of the blades curve, how do you handle that? What about the weapons that are lying on the ground with the blades visible? And like Dom said, you also will have to have the sabers reflect on the floor as well.