Hi @nesnes,
Thank you for contacting NXP Support!
1. What are the limitations with the i.MX8MP in this context?
As you mentioned, I can confirm that i.MX8MP doesn't support virtual channels.
The i.MX8MP can supports up to 2 cameras with MIPI-CSI interface.
2. Is there another MPU recommended by NXP that could handle this better?
Regarding, our MPU product family i.MX8 you can use the i.MX8Quad Max that supports multiple cameras.
Please have a look to the following reference to support multiple cameras:
Working With Multiple Cameras in i.MX8 - NXP Community