I have 2 questions about setting up OANDA asset list for Z systems. Thanks in advance!

(1) The leverages shown in AssetsOanda.csv range from 50 to 100. However, when I set up the practice account, the highest leverage I can select is 50. In addition, it seems there is tighter regulatory leverage requirement from NFA, mostly ranging from 20 to 50: https://www.oanda.com/resources/legal/united-states/legal/margin-rates

Question: do I need to manually change the AssetsOanda.csv file "Leverage" column to match the tightest requirement, and clear "MarginCost" column so Zorro will calculate margin cost automatically? Or can I leave them unchanged - I guess Zorro might get these info from the OANDA API?

(2) Document says default asset list is AssetsFix.csv unless script specifies a different asset list. Do I need to manually make a copy of AssetsOanda.csv and rename it to AssetsFix.csv? Or does the Z system script automatically select the asset list according to the broker selected?

Thanks!
-Zhong