To be honest it’s one of those things that is still kind of debated over. The problem is that the functions of the switches were slightly different in both movies - even GB1 was a bit inconsistent with the lights and sounds - and i think this is the main reason why each maker seems to do things differently.
In addition to this the packs and throwers weren’t consistent with the lights throughout the movies, so it’s hard to decide on how a bog-standard pack should operate.
For example, the ‘super-hero’ thrower had a scrolling bargraph which is what most light kits show nowadays, however the rest of the heroes had a static lit bargraph. The SH thrower also had a lit hat light next to the Clippard, which the heroes don’t.
This is why it’s so hard to nail down a single standard for the packs, so each maker has to come to a compromise of what they think best represents what was seen on screen.
I kind of went for a mix of what was seen in GB1, and this is how mine’s set up:
ACTIVATE turns on the pack and thrower lights, and gives power to the sound board (no sounds comes on yet)
The VENT switch (upper toggle) turns on the vent light and the ‘power up/power down’ sound
INTENSIFY fires the barrel light and activates the ‘fire’ sound
I also have the orange gun ear and white gun box hat lights lit with the thrower lights, and i’ve gone for pure ‘GB1’ light and sound operation (no vent sound, no overheating, etc.)'. Now this is a mix of the SH thrower and the packs seen on screen in GB1, but every builder picks a way of working they like the look of.
It is a really good idea to try and set a standard for the pack operation (i thought the same thing when i started getting into my builds), but the big problem is that the packs were so inconsistent on screen (even if it’s only slightly sometimes) that everyone has a different idea on how they should work. Saying that, maybe the issue hasn’t been brought up on a big enough scale before? Maybe if as many people possible had an input, something might change…