Yes it is possible to do what you describe. However, when you go from Atlas to Argo you will need to do the patching of the fifth universe and on.
So from what I have understood you find it worthwhile to upgrade to Quartet for 129, but not worthwhile to upgrade to Symphony for 695, which means you appreciate the benefits of Atlas. At least now the product choice lies totally on the project sizes on your side, and not on our side and which features we have chosen to put in the different products. Finally, since you mentioned waiting for next year there are no guarantees that the promotional price of 695 euros will be available. This includes a 30% discount and will be definitely there during the lifetime of Capture Atlas, but maybe not later.