Selganor
Adventurer
That's where I got the idea. In the campaign I'm in we find so much loot that I don't have the time and money to do schematics for all the stuff we get. (I got 21 schematics for my level 4/3 artificer/savant - but still a few days )If you haven't already, you might want to check out the revised artificer, which I believe addresses at least the first point (it was a big sticking point for me that he thankfully fixed). It's called Advanced Artificers, technically it's 3PP but it's the same guy who wrote the original A5e artificer for the GPG. Went through a lot of community feedback and updated it to make a much, much better version (IMO).
But I've played in quite a few other games where there weren't that many chances for an artificer to get schematics hence the houserule.