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Mode->Price Limit-> Never *PING *OVER *TopOfCurrentOrderBook Price *MINUS *0.5%

Ping/Pong limit are create against your last price, not market prices.
Your rules has not reason to exists :

Mode->Price Limit-> Never *PING *OVER *TopOfCurrentOrderBook Price *MINUS *0.5%

This will result in an order impossible to complete : your order will never be on top, so your pong will never be executed.
Your target it to stay in front of the top orders book, not constantly back (inside the order book)
with this rule you will be constantly back.

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Could you please add an overview where we can see what C.A.T. thinks is in the portfolio?

Data are returned from the API "MyBalance" that is needed in any exchange to let C.A.T. run.
I don't calculate anything. I only put the values Available/Held (if returned) in my internal structure.

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Yes, C.A.T. tries to place orders of 0.0000 quantity and then rounds them up to 0.1. Doesn't seem a good practice.

Well it's not 0.0000 it's 0.0000XXXX (because Pool is not empty), but exchanges you're trading on doesn't wants more than 4 decimal places, so inside the log is printed 0.0000.
some people wants to adeguate the order to the minimal qty.
You have an option, so you can choose what to do.
If you think it's not a good practice, disable the Always adequate option.