Wasn't covered on my rescue course.
Understood. I've always felt that my role as an instructor was to use my experience to enhance the standard curriculum, provide my students with practical skills and information. All instructors are required to follow the standards set by their agency, but most agencies give instructors permission to supplement the established "minimum" curriculum, provided they stay within standards.
If it's a full on out of gas or an uncontrolled ascent/decent then it's a lot more serious and is borderline CESA, especially as the person's obviously inexperienced and possibly at the edge of panic. When doing a CESA you must be able to control the rescued diver. It's a lot easier to do that if you reach out for the elephant's trunk where you can dump some gas, inflate OR orally inflate, especially if on the surface.
I really have no idea what you're describing here. A "CESA" is a one-diver operation: the diver that is out of air ascends by themselves. If you are a "rescuer" and close enough to "control" the diver in need of rescue, you should give them your alternate so they can breathe. There shouldn't be any need for a "CESA" if you're there to help.
Easier to reach for the "elephant trunk" to deflate a diver you're assisting?? I will respectfully disagree, but my opinion only comes from teaching rescue courses. I think popping the diver's dump valves is much much easier than trying to grab the "trunk", elevating it appropriately, and then hitting the deflate button.
Please... give dump valves a try. Once you start using them, you'll really like them.
And again, on the surface: if it's an emergency, drop weights. If the diver is out of air, err on the side of caution and drop weights at the surface. That should be simple, safe training... and then it doesn't matter whether the diver has a traditional inflator or an i3.
If you, as a rescuer, insist on helping a diver in distress establish buoyancy at the surface by inflating their BCD, but you can't figure it out... that's on you. Because you should have just dropped their weights. If you're concerned about losing a weight pouch, then just make sure you're fully inflated, pull one of their pouches and hold onto it. Everyone will be fine... i3 or not.
I do appreciate that I' may appear a little dogmatic about this and happy to apologise. Was only trying to make the counter point of the drawbacks when using such a unique system that many (most?) divers would never have come across before.
Dogmatic is good, no apology necessary... because as you've pointed out, there is safety in simple standards. I completely agree. And that safety is enhanced when the dogma is reinforced over and over, makes it more likely that people will respond properly in an emergency.
But dogma has to be tempered with rational thought, i.e. avoiding the automatic reaction to anything that challenges the dogma (such as the i3 system...) is inherently wrong and must be forbidden. In this case, the "danger" of the i3 system really isn't. It's a marketing gimmick, and (as I mentioned in the earlier post when I compared it to power seats in a car) it's a solution to a non-existent problem.