Well at least now I know for sure that this is way out of my depth and I can give up for the time being.
I don't suppose there would be a way of putting up a bounty to get armory working with the bgold version of bitcoin-qt? Is it a realistic possibility?
I've looked at their signer code, that part is easy, basically already done in Armory since it copies the BCH replay protection as is. Couldn't find anything about their new address format or any of their other changes, so I'd have to actually crawl through their changeset to get this done, and well... what's in it for me? Realistically, BTG is a 1% bump for maybe a week of work, mostly spent trying to figure wtf they changed in there, with the added risk of fiddling with signer and address code?
Bottom line, the reward doesn't justify the risk.
And by the end of the week its even less worth.
Users lost already a lot with claiming Scamgold.
Probably better to just forget about and if there are splits/forks in the future you could always create a signer for them if they have longer term value.
Users could always move coins to P2PKH addresses before a fork/split and can easier split them that way if they want to.
Armory is also open source so if a decent dev team is creating a fork/split they could probably also submit a PR what goatpig could check and commit then or create a separated release or whatever.
If I would create a fork I would make sure that most wallets support it but most just want to get rich quick by creating forks without investing time and money into development.