Sorry I don't know. I expect that there are Linux memory structure limits that correspond to maxlanport.
200 is non-sensical because there are no CPU's that can support that number of PCIe channels.
Ignoring the fact that significant scale-out aggregation does not result in useful performance unless you have comparatively scaled-out utilization (many users), you can aggregate as many devices as DSM can see. The most I have ever used, or observed anyone else use, is 4.