If I ever got around to improving the bubble test, I would've tried using Tails there. And yes, with the lightning shield, Tails can get soon enough to the pre-switch area; that's one of the three improvements I made to the lightning route. The other two were using the light blue path, and starting the Tails carry from higher up, before the downward slope.
Here's the bubble route:
http://dehacked.2y.net/microstorage.php/info/811955120/aa4.gmv
Here's the lighting route, v2:
http://dehacked.2y.net/microstorage.php/info/307348212/aa4_lightning2.gmv
Before I tested the shields, I had done a sketch for (almost) the whole zone using the bubble shield. The beginning is slightly less efficient than in the bubble test. There are some details that may or may not be of interest:
-The bubble bounce didn't really bounce at one point. The effect depends on where the bounce hits the ground. This allows a faster descent, and may be useful somewhere, but not here. I'd like to know more about this.
-I bounced through the mechanic stairs directly above the lightning shield box. This is the reason I wanted to extend the tests a bit, but it only matters if you want the lightning shield back as soon as possible.
-Using Tails to get to the highest parts of the level
might save some frames, if he's available. This happens slightly after frame 11750.
-To get the five rings with horizontal spikes on both sides, I didn't use Sonic; I dumped Tails there instead. Probably saves a few frames and causes big problems later, since Tails is lost.
And here's the recording:
http://dehacked.2y.net/microstorage.php/info/1607364091/aa3.gmv
I made all of the recordings as continuations to the one I already posted; thus, I didn't collect any of the bonus rings. I'll probably switch to newgame+ in the future. AIZ2 begins somewhere around frame 9500 in each of the recordings.
If I posted the same recording twice or something silly like that, I'll correct it tomorrow - the file names don't really help much in finding the correct file. I should get some sleep now.
EDIT: One thing I probably should mention: I missed one ring in the test run, but didn't bother fixing it - I'd have remade the run, anyway.