Kemper power rack impedance matching with cabs inquiry

I have a powered rack Kemper and also have a Mesa Boogie parallel box which enables me to run two cabs in parallel with one output. Can the Kemper handle mismatching cabs?

Example: 2 4x12 cabs with one at 8 ohm and one at 16 ohm.

So somewhere around 12 ohms when these 2 cabs are hooked to the Kemper in parallel.

Is this okay or do you have to run two cabs of the same impedance?

I thought the Kemper could do down to 4 ohm but am not sure about the odd impedance or if I am incorrect in thinking that the 8 and 16 ohm cabs in parallel would produce roughly a 12 ohm load to the power section?

I guess one step further would be can you run an 8 ohm cab with its extension output to a 16 ohm cab instead of using the parallel box? The extension on one of the cabs is parallel out as well.

Thank you for any suggestions.

I think the unbalanced level in unmatched cabs will keep me from trying. I do have other cabs of same impedance but wanted to use my Mesa 412 with a Randall 412 but one is 8 and the other 16 ohm. I will just run another 16 ohm Randall instead of the Mesa. Thanks everyone