Hey Tai,
Yes, most of the brokers offer different spreads for the currency pairs. I use this broker just for trading Cryptos. That is why we didn’t list it in the trusted brokers’ page.
And then, the different spread forms different Historical data, which means that you have to use the Live data in EA Studio to generate the strategies, not the Demo data.
With Dukascopy and JFDbank, the issue is minimal.