To "look ahead" to the actual entry price when calculating position sizes, specify QtyPrice: FillPrice.
The following are all equal position sizes:
When using Currency Conversion, note that quantities calculated with QtyType: Shares are NOT converted. Quantities expressed in Shares (or Contracts) are interpreted as verbatim share (contract) counts. Divide your Quantity formula by FxRatio if you want your shares-type quantities converted. Quantities calculated as Value or Percent, on the other hand, are always FX-converted automatically.