Fork. Stephen submitted a comment before this one.

Re: Robin
It is my understanding from reading here that the jisho.org maintainers are pretty responsive.  Is there a chance someone with existing connections could make a request:

    Please don't display the "usually kanji" or other kanji-dependent tags (eg. [gikun]) when no kanji are displayed due to [sK]?

Re:Marcus

I had/have the exact same viewpoint. From the vantage of studying kanji, rather than studying vocabulary, I like seeing these forms even if they are rare.  But I defer.
Here's the github discussion for reference:
https://github.com/JMdictProject/JMdictIssues/issues/75#issuecomment-1435712638

I don't think it makes much sense to hide away a rare kanji form with sK. Who's going to search for it considering how obscure it is? Why not have it marked rK instead, letting app developers etc. decide how mudh prominence they want to give it?

On 1011300, it was tentatively decided that [uk] should be kept on entries that only have sK kanji forms, out of consideration for websites/apps that don't support the tag.

@@ -13,0 +14 @@
+<misc>&uk;</misc>

Removed [uk].  Only kanji are [sK], so not needed.

@@ -14 +13,0 @@
-<misc>&uk;</misc>