I just tried again now as only 5 hours left before the challenge ended, but still got no luck the second time around. I risked the $8+ for this session but recovered the $5 on the dice game. Maybe this is not my time yet and will succeed maybe on other challenges. At least I already tried and got the experience on this in-house slot game and I have fun with the sound and animation.
The advantage of Stake.com is that you can bet the smallest amount and don't spend too much balance. Therefore, always move from one casino room to another if you feel you don't find many multiples. I often do that to get a feel for every space and look for some tight wins.Will that make you win more? Like if you wager the bottom smallest bet and then keep doing that in different places until you get a win? I doubt that would have any different result than betting on the same place, because I always believed that people will lose when gambling, house always wins, but if you say you would have more fun, then it is a great idea.
In any way... whatever I receive, will be coming out of the losses I suffered today. 
When setting your limit at 400 spins with $0.03 bet, you are not risking $12, because it's impossible to lose every spin out of 400. 
