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Minnowbooster are big investors and serious players. They have the ability (and responsibility) to spend more attention and time on their code.
I am just a dude with a computer. I work on the bot only until my wife becomes angry and starts pushing me away from the PC.
Do not expect me to work on the same standard as them.

Well I am the main coder for minnowbooster ;) We may have a team that helps with many things but the code is still mostly done by me.

If you need advice on how to detect many problems with steem, I may be able to help you implement them. Many are really easy to fix once you know it.

Most of these errors got fixed by a user complaining, me checking on what happened and what a clue was, that something is wrong, then just sending the money back once I notice that clue.

I fixed problems in similar manner.
The biggest difference is the time I am willing to spend on fixing problems.
I am a lot less invested in Steem, after all.

As for difficulties - so far I haven't had any.