ADC configuration with MCSDK6 - options and implementation

[DMeie.2]

We need to implement a number of additional ADC channels in our custom board, on top of what the motor control application requires.
The MCU in question is the G431, the overall inverter design is based on the B-G431B-ESC1 with FOC and three-phase sensing enabled.
The MCU provides 2 ADCs, both of which are used by the motor control application.

For implementing the additional ADC channels, I added them as single-ended ports via the CubeMX to the motor control project.
Now I'm wondering, what are the limitations that I face? Which options in the ADC configurations can or can't I modify (speed, analog watchdog, oversampling)?
Can I use DMA?

How many custom application ADC channels am I allowed to add? I need at least 5.
Could I also use the additional ADC1 options like temperature sensor channel and Vbat channel?
How do I work with these custom application ADCs? According to some topics I found for older SDK versions, I need to use the "Regular Conversion Manager" for this.

[DMeie.2]

One additional related question:
The board is configured in a way similar to the B-G431B-ESC1, with the current sensing using both ADCs. I suppose this is required since the design uses the MCUs OpAmps.
This is not necessary in our design as we are using a driver that already processes the signals ("CurrentSensing" is thus set to "ThreeShunt_AmplifiedCurrents").

Due to this, could I actually free up one ADC by setting all by the motor control required ADCs to a single one? Should or can I still use the Regular Conversion Manager if that is case?