Thank you both for your responses! Someone told me wrong about BG1 & 2, claiming there was dialogue in BG2 that indicated svirfs weren't welcome in Baldur's Gate still. And that the Gondians helped Gorion's Ward? I couldn't find anything about that. I think they just misremembered.
I'm still confused about why Gaerdal Ironhand would have any rivalry with Gond when they're technically of different domains and Flandal Steelskin is supposed to have a portal to Gond's workshop or be strong allies with him? The only relevant information I could find in Forgotten Realms sourcebooks was a single quote in Faiths & Avatars saying "Gnomes may be Gondsmen. This vocation is frowned on in most gnomish communities, but Gond is slowly gaining acceptance among gnomes." (page 63)
Also trying to figure out whether or not "Nebelun" is the same god as Gond has been very confusing for me since many sources differ on it!
In BG3 there are a couple books in Gyldro Angleiron's that sort of explain Wulbren's entire rivalry with them, though.
Ironhand Gnomes: Our GrievancesRunepowder and the Modern GnomeI can't figure out how to include images so I'll link to them instead...
It's my belief that
Runepowder and the Modern Gnome was written by Wulbren's grandfather, and
Ironhand Gnomes: Our Grievances was most likely written by one of his parents? Or at least dictated to him, since he would have no way of knowing himself. So I suppose the Bongles are from this traditional gnomish background where they think it's wrong to follow a non-gnomish god, as if it's abandoning their people or something.
Given the time between Gond's avatar arriving in the form of a gnome in Lantan (1358DR), after which a lot more gnomes started worshipping him, and the events of the first Baldur's Gate game (1368DR) were ten years apart, I could see them still being slow to accept the change (it's wrong, but I could see them viewing it that way). The smokepowder part definitely adds urgency and conflict because it's way more of a war domain thing than an inventor thing, and having the biggest weapon is a huge threat. And it might explain why this "Unfortunate Runepowder Incident" even happened. I imagine old Wolverforce obsessively trying to outdo the Baldurian Gondians by proving he has the biggest explosive. ;P
I think a lot of the plot must have been personal, since their actions didn't align with everything I could find on being an Ironhand follower and the Grievances book is obviously propaganda. It's just mortals being wacky. And since svirfs apparently don't really have documented or well-documented history, they might just believe whatever anyone tells them about their past.
Well I'm glad to find out it seems like this conflict was entirely made up for BG3! Why, I have no clue, the decisions are kind of odd and some things make no sense or seem unfinished, that's also probably one reason I got overly invested in it (is it a mystery or are there just no answers to be found?). The idea that the Gondians would just say no to the Ironhands allying with them before for years when they weren't actively threatening them is confusing lol. (Unless they were? Idk that's never expanded on. You don't want more hands on deck to help you build city infrastructure?) But it was still a very fun, dramatic part of the game to me! Never thought I'd become this interested in svirfneblin lore, or Gond, of all gods haha.
Also I apologize for not thanking either of you earlier, I posted this thread in the middle of the night during a manic episode and genuinely did not believe I actually posted it. Whoopsie!