Expose all parameters prior to clicking generate button

[gowthamrao]

We know some pages take long time to load. So pre-selecting all parameters and then pressing generate button makes sense. However, not all buttons are exposed. This makes us regenerate tables twice. eg.

The following are exposed - i make selections -- press generate

I wait --> A report comes -- but now i have more options -- other buttons i want to select..

if i make changes --> i wait --> regenerates the table.

is there a way to make it so that i can avoid the double generate problem? Also the second set of buttons are not linked to the generate table button (i.e. they are reactive. so each selection change e.g. select proportion (wait for generation), then select group by time id (wait for generation).