I just did the exact same test as lofreq, with the same results.
I flashed HJ 286 and did the standby/recover thing and I got the 3-4 second delay, the slow screen fade in and the battery icon.

I then flashed HJ 253 (unfortunately the only older version I had before 281. And it appears all the old HJ versions are no longer downloadable from the hijack website) and I got a much quicker return from standby, and no battery icon.

Something definitely changed somewhere.
If somebody wants to send me HJ 278 and 279 I can try those as well.
So it would appear that this is not a result of wiring (phew) but a change in the code?
Maybe it only effects certain cars though? Due to different wiring schemas?
I dunno... Just know its broke in my 95 VW.

Zachary