XMC4800 external multiplexer: more than one possible

I'm having a hard time to understand the VADC module of the XMC4800. I read the manual and the VADC app note AP32305, but still not sure about the following:
I need some more channels, so I would like to add external multiplexers. I understand the basic concept and I know how the VADC will use the dedicated EMUX pins.

BUT here are the questions:
1.
Does the concept of "Request Sources" support more than one external multiplexer per VADC block?

2.
I see two external multiplexer groups, EMUX0x and EMUX1x - is this per VADC block or is this shared along all 4 blocks?

3.
To take it to the extreme: Would it be theoretically possible to extend each channel available with an external multiplexer and this would still fit in the concept with automatic channel selection?

Thanks for reading!