I know what you mean , yet there is an easy way around it
you can have multiple projects open in SONAR …I do it all the time … there is nothing to reload ..
when you hit minimize , you can see all the open projects over by the lower end of the task bar …you can always maximize the project you want to edit ...
what about doing something along these lines ...
get your mix to where your as close as you think you can get before you want to experiment ...
on that mix do a save as and call it by its song name and add mix 1 to the title ….
while leaving that song / mix1 project open , reopen the original project …be bold , take chances , edit it to your hearts content …then all you have to do is minimize the project and pull up the other one …mix 1 and compare
if you did something you really dug call it by it's name and add mix2 when you do a save as ...
it is really that simple and there in no load or reload time involved
hope that helps you in the mean time ,
Kenny