I know this is crazy, but it's a showstopper.

There is only one photo editing raw-format application available for Linux -
Corel AfterShot Pro.
https://www.aftershotpro.com/
(Free packages can be downloaded for trial, no registration needed.)

Its tech specs requirements are out of date, but the download page says
https://www.aftershotpro.com/en/free-trials/aftershot-pro.html
Ubuntu 16.04 or earlier - 64-bit
Ubuntu 16.10 or later (not Unity) - 64-bit

rpm -q --requires AfterShotPro3
libgstapp-0.10.so.0()(64bit)
libgstreamer-0.10.so.0()(64bit)

I found them in home:cabelo:games (for 15.4), and am very grateful for it.

Could they please be put back into the main OSS repo?

When one has to edit 150+ photos from a photo shoot efficiently, gimp simply
doesn't cut it (I have doubts it even manages to edit a single raw-format photo
because there is a lot of proprietary rubbish in there). There is no other
option for Linux, plus it is affordable - photoshop is not.

Before anyone says some commercial supplier should just package up properly,
that is all true but we know when that will happen. Given infrequent updates to
AfterShotPro I'm hoping Corel won't be discontinuing it.

With current tumbleweed being completely incompatible with 15.4 (everything
tumbleweed barfs on 15.4) this issue is only going to get bigger.