so, empty - about 200mb, when i loaded one of the larger projects (6 voices and 3 minutes long) i see it jump to about 2.1gb while generating, then once it’s all stable, about 750mb. which when i do edits, then shifts upwards to 1.2gb for the processing.
so i’d probably plan on 2gb needed for working. as a note: i generate the vocals in the standalone app. i export a non-vocal 2-track WAV of the instrumentation, which i import into the project and then work against that rather than loading it into the DAW (which in the pro version supports ARA2 – but not all DAWs do…)