Multi Currency Ticks and Bars eat Tons of memory. Load history starting from a certain date / or a maximum number of Bars or ticks

When running Multi Currency Ticks and Bars take up gigabytes of memory
A lot of that information is not needed when I only want to go back for lets say 5 days.

Would be nice to load bars(MarketData.GetBars) and ticks (MarketData.GetTicks) starting from date yyyymmdd only (preferred)
or a maximum number of bars / ticks.

Or to be able to delete ticks and bars from their respective collections.