ArcGIS Pro really needs better, ArcMap quality, options for layout of ModelBuilder models and especially connector display.
The fancy "Bézier curve" connectors make complex models extremely hard to read, and thus hard to use, this is real problem for modifying and maintaining of such complex models.
See the attached screenshots for examples of two models both displayed in ArcMap and Pro.
It would be really helpful to have an ArcMap style "straight line with sharp angled bends" connector type option in Pro.
At least with straight lines, one can see where a connector is coming from and where it is going, even in an extremely complex model like the second example with many interconnections between (sub)models. With curves, it just becomes a total guess...