[wp-hackers] Is WP_INSTALLING constant here to stay?

[Mike Schinkel]

On Jan 22, 2013, at 12:29 PM, Andrew Nacin <wp at andrewnacin.com> wrote:
> I would avoid this. Here's but five reasons why:...


In general, 99.9% of the time I agree with you. However there's one use-case we ran into where we had to do otherwise and I'm wondering is there is a way to do it the "right" way and still meet the UX requirement? 

We were building a Facebook-like predictive search drop-down and we ran into latency issues that the person developing it said he could only resolve the latency issues by directly loading a PHP file via AJAX and setting the SHORTINIT constant to true before including wp-load.php.  I won't name the person who wrote it but he has an extremely high reputation on WordPress Answers.

So how would you in a plugin set SHORTINIT which bypasses loading plugins and still use WordPress' core AJAX handler given that SHORTINIT is crucial to achieving reasonable latency?  I really hope there is a way to do this but looking at his code I can't currently envision what that would be.

-Mike