Hi Lucio,
It is a limitation with wave-1 APs. Refer the What's New document for 200.7
here.You can buy a ZD1200 and manage upto 150 APs. R500 is still supported on the latest ZD version 10.4.1. Find the data sheet
here for ZD1200 and release notes of 10.4.1 from
here.

Regards,
Syamantak Omer
Syamantak Omer | Community moderator | Staff TSE | CWNA | CCNA | RASZA | RICXI | Follow me at https://linkedin.com/in/syamantak-omer-5949b6124