To answer your question in general, Yes, Qlik allocates more memory for bigger applications.
But there are a lot of factors you need to consider to "balance" Qlik resources.
How much memory do you have on your QS server(s)?
Will you have data load and user-facing servers separated?
Will you use incremental or binary loads?
Will you use section access to reduce the app's data?
How many users will be accessing your application at the same time?
Answering these question might help to understand your case better.