I don’t have a solution to offer, but am just acknowledging that I see the exact same issue on my Mac mini M1 – an image processed with Silver or Color Efex 5 (for example) “blinks” multiple times before it finishes updating in Lightroom. If I try multiple images as a batch, they all do it for quite a while before Lightroom is updated with the changes, sometimes never finishing before Lightroom locks up.
I’ve had some success with a workaround: creating the initial TIFF file with Dfine 2, applying noise reduction, then after that’s updated in Lightroom, sending the image to Silver or Color Efex. If you decide to try that – it hasn’t worked for some folks posting here – you should first set the Dfine 2 app to “Open using Rosetta” in Finder (otherwise the image will open pixelated).
There is a long thread at NIK 5 crashing Lightroom that describes some of the other things people tried to get Nik 5 to work correctly with Lightroom. None of them resolved the problems; just letting you know what others have already tried.
At this point I’m sending my images from Lightroom to Photoshop (using “Edit in Adobe Photoshop 2022”) then opening Silver or Color Efex from Photoshop. I wasn’t accustomed to doing that (with previous versions of Nik I had only sent them from Lightroom), but now that I’ve gotten used to it, it works well and I still end out with all my processed images in Lightroom’s catalog.