So I'm browsing my phone with iFile and I've come to realize that in my "Assistant" folder, there is no com.apple.assistant.plist file. Isn't that absolutely necessary in order for Siri to work? So I went through the whole process all over again, uninstalled everything that has to do with Siri and even deleted the Assistant folder afterwards (knowing a new one would be created again). So I turned off Siri, deleted all certificates, rebooted, removed Spire, rebooted again and then reinstalled Spire, the certs, and finally the proxies. Still no com.apple.assistant.plist
Pretty bad luck for me, as it appears my phone will never have Siri functionality. I'm $35 poorer, and basically feel like a dumbass for even trying any of this. Take this lesson far into life - a fool and his money are soon parted.
😱