I am connecting to SharePoint online list which only has 120 records. Not so complex business app. But still take 15 second to load app and extra 12 seconds to load data of my list (which is filter by defalut to only show 50 items).
That is a important one which has been reported from Mid 2016.
If it doesn't fix, it means that the apps not going to pruduction ever so both party (we as a developer and you as a product owner) just waste our time.
Thanks for your great effort and improvment but please fix most important issue first.