I've read that the Viltrox EF-M2 II has updated optics and performs better than the first version, but I'm wondering if the Viltrox NF-M43X has had the
optics updated or if it still uses the older subpar optics?

I know Metabones is the undisputed best, and I'd probably buy one if I owned a MFT camera, but the Viltrox focal reducers are so cheap that I'm tempted to get one for use with rental cameras.

Sorry if this question has been answered before, but I couldn't find anything in a search.

P.S. In case anyone knows, same question with the Viltrox E-mount to Nikon focal reducer, does it have bad optics or have they been updated?