I was going to post the cards Squee1968 posted with a few minor fixes but in testing has pointed out a few other problems.
Firstly, it turns out that the "if CARDNAME was cast from your hand" bit was never implemented in
Furnace Dragon in the first place so none of these implement it either. I remember avoiding these cards in the first place because I couldn't see how the trigger was limiting it just by having the stack as origin seeing that all card end up on the stack when cast from anywhere. So I haven't added any of these yet (however, I did fix up the Remember on
Wormfang Behemoth, so thanks for pointing it out,
Squee)
Secondly, there proved to be some errors in the cards I was using to test the situation (the only card that helped successfully test was
Temporal Aperture):
-
Jhoira of the Ghitu is exiling the card from your hand without giving it suspend
- When I used
Horde of Notions to try cast
Coal Stoker I just got a crash, but I think I recall there being other reports of this when using HoN's ability.
EDIT: I haven't tested
Furnace Dragon itself, just the cards templated from it, but I don't see any hardcoded bits or script that would make it any different.