Store downloaded historical data in Backtesting mode, instead of downloading every time?

Hello again,

do I have to download historical data every time? Would it be possible to bulk download all data from a pair once and only download missing data on next restart? It feels strange to sit and wait every time, especially for long term testings. But maybe the option is present and I dont know? 

(And just a quick compliment, I really love cTrader. For me it's the best platform I tested so far.)

Cheers