Glad to hear from you. EA Studio requires json files for the Historical data and the collection. Not for the Expert Advisors. I do doubt you can upload a purchased Expert Advisor in EA Studio because the source course will be different most probably.
I am curious to know if there is a way to upload my own expert advisor that i purchased from somewhere into expert advisor studio so that i can tweak it. I see the system provides for importing JSON file only. So is there a way to convery my own expert advisor which is an mq4 file to a JSON file