The way I do it for example is as follows: In expressgenerator I will create strategies for 01/01/2020 through 10/01/2023. Then I will import the strategies in EA Studio with the date set from 1001/2023 through today. The result is the OOS test. It will not be green but it is an OOS result since the strategy was created from 01/01/2020 through 10/01/2023 and EA Studio is testing out of that sample.
Alan,