Feature request - some sort of alert or visible warning when you would be necroing a thread

Example.
(I just chose a random thread like 20 pages back)

Would need to show up both when simply posting in the thread, ie, the message editing form at the bottom of the thread page, as well as when responding via clicking quote and getting taken to a new URL to write your reply.

Threshold for when the warning pops up... is debatable, and could make a lot of sense to vary across the sub-forums... Maybe never show in Lost and Found or Memorial, show after 1 month in FOR SALE / FOR FREE / WANT TO BUY, show after 1 or 2 weeks in any partner finder forum, and show after 6 months everywhere else?

I imagine this could potentially cut down on pointless accidental necroing quite a bit. It doesn't stop one from posting, but it would make them think twice about if their reply is relevant, particularly on a time basis.

I kind of like the ol' fashioned way of ridiculing someone that responds to a four-year old thread. What's wrong with looking at the date of the most recent post?