Planning in APO but MRP still executed in ECC

Hi Experts,

Our scenario is to plan for the FG in APO, transfer the forecast & firmed planned orders into ECC but also have the ability to run MRP and create proposals for any shortages there. The requirement is set this way because sometimes the firmed planned orders transferred are sometimes lower in quantity than the demand (business mandate).

Now I understand that materials planned in APO have an XO MRP Type and MRP is turned off. My question is what is the impact if I edit the XO and turn on MRP?

Conversely, I could create my own MRP type (ex. ZX) as a copy of XO and turn on MRP for this but my question, will this cause a problem in the CIF back to APO from ECC?

Thanks