There was a similar questions about the Nik collection on another forum (not much use to me using linux) so I downloaded to check what happens. 429 MB download - bloatware. Still have it archived though

However, just gave it a try out with a portable Gimp 2.10.8 from Partha, regular installation is the same.
Run the installer, there are the usual language and can we phone home options, then you came to the destination folder
Use the Default installation location The Partha plugins are set up for it. Ignore the compatible host application and install.
Attachment:
01-nik.jpg [ 95.52 KiB | Viewed 5787 times ]
If you were feeling clever and installed to a different location, or you computer is set up in some other way, there might be language issues I do not know. Edit the Partha scripts to reflect the Nik location. Never tried it, do not advise it. Look for lines like this
# Build command line call
command = "\"C:\\Program Files\\Google\\Nik Collection\\Viveza 2\\Viveza 2 (64-Bit)\\Viveza 2.exe\"" + " \"" + tempfilename + "\""
Once installed, check that it actual works without Gimp. Go to the Nik installation folder and find one of the filter
executables and run it, see if it starts.
Attachment:
02-nik.jpg [ 50.93 KiB | Viewed 5787 times ]
Now you can check it in Gimp, a little dialogue about what to use and the active image opens in Nik. Tweak the settings, Save.
Attachment:
03-nik.jpg [ 94.07 KiB | Viewed 5787 times ]
I get a little error message here, of no consequence, close it and continue.

Is it worthwhile? I think most of these effects can be obtained in some other way / some other plugin.