To submit suggestions for new or changed features, may I suggest: Feedback: https://qsurvey.mozilla.com/s3/FirefoxInput/

Mozilla has a command-line utility for bulk operations on the cert8.db database which stores the certificates. This is not to say a search feature will never be implemented, but if you're in a hurry, you might need to dump it out...

https://developer.mozilla.org/docs/Mozilla/Projects/NSS/tools/NSS_Tools_certutil

Note that there is some searching feature that works with treechildren type content and that is to click in the content area to set focus and then quickly press the first letters of the name to search for (e.g. sy brings you to Symantec).

All are good/helpful responses, yet nothing "quite it": Is it "necessary" to mark "Solved" for a response?

There is currently no real solution and we can only offer workarounds that we are aware of.

You can mark your above reply as the solution if you want to close this thread,

Well, if "it is okay" for a support question to remain open, then I needn't mark anything.

Otherwise, I'll mark myself. :-)