Sure, good call. It's 6.498 from Sep. 5th, 2021, might not be the latest or the most relevant, true.
Well, it’s the only other method of launching GC games I have at my disposal, and it’s easier to count pixels on direct capture from it (while I don’t have a capture card), but yeah, the HW’s behavior is truly definitive, which is why Dolphin is more of an afterthought in my post
"Force Widescreen" is turned off (I'm trying to get 4:3 out of the game). All of the video options are set to Auto, though changing them doesn't really help either. Video Width is the only one I hoped would work, but it doesn't.
If it matters, this is a PAL Wii on 4.2E (last updated when 4.3E wasn't out yet) set to 480p in the system menu, the game itself is a 1:1 copy of the US GC disc (I live in the US now, so getting PAL games here is not that easy I think). The TV itself was also purchased in the US, though it shouldn't matter.