True, the margin is too low for the capital. I suspect that reducing the asset list to just a few assets also reduces market participation, since probably only a fixed maximal fraction of all assets in the list are traded, and each likely has a participation cap.

However, even if we keep the standard asset selection, maximal open margin is about $3500 and that's even though Equity has grown to $15000! Way too small participation, definitely needs to be reballanced in my opinion.