The issues you mentioned when connecting 2.0 devices on 3.0 ports might happen depending on how the ports are configured by your motherboard and sometimes can be manipulated to some extent through BIOS options, but that varies a loooooot from manufacturer to manufacturer. In general, especially with recent hardware, there shouldn't be any behavioral difference when connecting a 2.0 device to a 2.0 port vs connecting a 2.0 device to a 3.0 port...
Avell A70 MOB: Core i7-11800H, GeForce RTX 3060, 32 GB DDR4-3200, Windows 11 (Insider Preview)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)