Take a look at this screenshot of some custom operators. Note that the first two are only partially colorized as a custom operator, but the third one is completely.

In other files, if I use the third operator, it is colorized correctly, and I can hover over it and see the /// comment, and I can navigate to its definition with F12. But not for the first two.
In this screenshot, you can see a use of the first operator - note the color. As noted above, expected behavior (e.g. F12) is missing.

But, all three custom operators work as expected (in appearance and behavior) in Rider (Windows and Linux).