Load will always mean to reload the complete application. This is per desktop client quite easy but per access point quite difficult and it will have various side-effects.
Another way could be to chain several documents - maybe you could find here a practically example: https://community.qlik.com/search.jspa?q=document+chaining
The first thing which I would try would be to optimize these application - and quite often there could be optimized many things. It would be helpful if you provide more details - number of records, used fields, which kind of data, where are the performance issues and so on ...