Since you have not changed anything but still the loading time increased, I think it’s simply because of your network speed which might have been slower when you tested.
Also, the theme.css takes a lot of loading time as well. Can you please check the time it takes to load the app after removing your Theme.css?
My question is, if everything is compiled from top to bottom, then the first print() function must be the first thing that is executed. Meaning all the imports are happening after the print() anyways.
Do you know what files/components are loaded before the first line of a startup form gets executed?