Many here may have already heard the news. I posted how to get these to work in the GIMP via shellout, here. Since posting, I found that you can actually replace the jpg link with tif but you may get errors. The reason this is better is you can work with images lossless and also with alpha channel intact. 
There is a bit of discussion here: Nik Collection free now. Good for Gimp and RT
Problem is that those programs are not libre.
Guess I didn’t do a good enough search. Thanks for that.