I also noticed that the high quality blending is very noticeable in layered refractive materials with bump, possibly refractive materials with bump in general. This actually isn't all that surprising because the seams of the tile blending create enough regular noise that must also be refracted, as to be noticeable. I'm not sure there could be a fix for this given the current implementation, i.e. the shading is rendering correctly, it's just that the blending method is so noticeable in a refractive surface.
I have just tried it (but very quickly) and here is the UI. It definitely looks less user-friendly than Corona's version, but I have no idea about the usability. It would be great to test it thoroughly at some point. One advantage is that it can be previewed in the viewport.
From the Corona Renderer 6 Daily Builds Changelog:Added (randomized) tiling support to UvwRandomizer map:- You can specify how many tiles to make in each (U-V) direction- Optionally each tile can have different randomization applied- https://corona-renderer.com/comparer/hCPRU4- https://corona-renderer.com/comparer/7wCz5x- https://corona-renderer.com/comparer/CDkWvEHow it works:To enable tile randomization, navigate to your UVWRandomizer texmap, and enable Randomize each tile. You can then control the number of tiles and tile blending accordingly.Setting UV offset ranges above 1.0 and W- Rotation to different ranges (f.e. 0-360) will assist with the randomization of the texture.Note: Either an object with correct UVW mapping is required for this to work (unwrapping or UVW map modifier), or you can use the UVW Randomizer in combination with the Corona Triplanar map to both randomize the texture and prevent seams and stretching, without the need for UVWs.Feel free to post your results!You can always get the newest build at the usual location: [Link]