Wikipedia:When not to link to WP:NOTNOW

While adminship is intended for established editors, occasionally enthusiastic newcomers decide to visit requests for adminship and give it a try themselves. Typically these attempts are quickly closed following a barrage of opposes linking to the essay WP:NOTNOW. When the candidate clicks on the WP:NOTNOW link, they will see an essay that explains to newcomers what adminship is and why it's not something that's "in their league" at this time. Ideally, the newcomer will read the essay, recognize that the opposes weren't personal, and gain a better understanding of what adminship is and is not.

On the other hand, occasionally a long-term, established editor will appear at RfA, and for whatever reason – perhaps poor answers to the "optional" questions, or inadequate experience in certain areas valued by RfA participants, or temperament concerns – some people will oppose their candidacy. They may even say that while they are opposing now, they will be open to reconsidering later, once the areas of concern have been addressed.

Sometimes these opposes will include a link to WP:NOTNOW.

This is not a good idea.

What WP:NOTNOW is not
WP:NOTNOW is not intended as a shorthand for "I do not support your candidacy now, but I might later." It is intended as a guide to help newcomers who genuinely don't understand what adminship is, and to explain why editors without thousands of edits and months (years in some cases) of experience on the project are unlikely to succeed in a request for adminship.

If an editor: ...it's a good bet that they know what adminship is. There's no need to send them to an essay designed for new editors who may genuinely think adminship is something any editor with dozens of edits and a couple of weeks (or days) on the project can obtain.
 * has been active for several months if not years,
 * has accumulated thousands, or tens of thousands of edits, or
 * has audited content contributions, such as good article credits...

Linking an established editor to WP:NOTNOW insults their intelligence, and implies that they should have known better than to request adminship at their current level of experience. If the candidate has waited until they have thousands of edits and/or audited contributions under their belt before requesting adminship, they have already demonstrated that they understand that adminship is not for newcomers.

Instead, if you feel that an established editor is not ready due to deficiencies in their contribution history or their approach to other editors: just say so. Don't link to an essay just because the words in the title correspond to some of the words in your oppose rationale. WP:NOTNOW gives no guidance to established editors as to how to improve their chances at a future run, and was never designed to do so. Instead, if you are willing to consider supporting the candidate in the future, offer them your honest (but polite) feedback as to the changes you will need to see for them to gain your support. That honest feedback will do the candidate (and any other editors reading the RfA and considering a run of their own) infinitely more good than linking to an essay designed for an entirely different purpose.