There are some nice blog posts about performance: https://www.mansystems.com/blog/how-to-speed-up-your-mendix-app-part-1
Most important, see if you can narrow down the chart or mf that causes the main part of waiting. First thing that comes to mind is to use lazy loading. You can try to ease the first load by only showing the light charts and mf’s in a tab. Make the others hide in another tab. If I am not mistaken these will only start after opening the tab.
If it is a microflow taking its time, certainly for a report, probably a database retrieve takes a long time. If that retrieve is not straightforward but somewhat complex then it can be an option to use OQL or even create your own SQL. More often than not they are faster compared to the MBS.
I would love to see more tips here, since performance is not Mendix’ strong suit.